You need to get the contractor back.

agree w/MongotCT as likely cause

its clear in the middle pic the grout is proud in elevation or were all blind :) We would need to know

more about substrate , mud bed used or if you have a foam preslope pan but your drain grate looks like a zern or smith and leads me to think its a clamping weep drain if so a properly done dry pack and protected weeep system is intended to pass water if done correctly.

Im also seeing efflorecense. share more facts and pics or theres not much more any of us can say. A second opinion onsite from a different tile pro is not a bad idea (Tile Pro mind you)

To be sure iits not going to magically correct itself :(:(

What a optical illusion. What we see in the photo's is glass mosaics. We are actually looking into the tile. Yes poor choice of material. Ghosting is visible throughout.. Sorry I was typing when you posted.

When he sees the pink tiles - he cannot deny something is wrong.

In your second picture I can either see the tile backing? Maybe water has gotten between the tile backing and the thinset? Do you have any left over sheets of tile - what does the backing look like?

I have never installed glass tiles on a shower floor - but I know the glass tile manufacturers have some pretty specific specs about thinset.

I'd contact the tile mfgr and send them this photo. Is the tile suitable to be used on a shower floor?

When we install glass in a shower pan and it is very risky we first do a soak test of the mosaics . There are a lot of mosaics glued to sheets with a water based re-emulsifiable adhesive that can wreak havoc with unbonding and mold. almost always I remove tiles clean adhesive and set one at a time . You may have latex based adhesive leaching and molding but were guessing here based on experience albeit. I am certainly seeing the sheets thru the glass now .,

Theres a lot to it and I fear you are attempting to translate "what you think was done" and we need undebateable facts. :)

Anytime there is a mud bed if not done properly or the wrong mix is used there is always a chance of eflorecense thru the crete and saturation so you may have many things going on

And WOW what a real optical iilusion as CTEC stated. Looking closer at the firstpic @ perimiter of floor mold is evident.

This is why Pro tilers Buy the tile itself, supply all materials and take that liability also knowing what to look for and verify and that comes at premium professional rates and with detailed scopes in contract., gets dicey when a homeowner supplies any of the tile or material. A true tile pro will pass on the project 9 times out of 10 .

The pink likely is a type of bacteria and precursor to future mold usually brought on by soap fats and body scum.. I cant see your contract and warranty and you are in a pickle with it. Ask yourself if you want that person working on your home again? and then look close at what you yourself shopped for and ended up getting it sounds like you are open to being honest w/yourself.. There are actual tile professionals out there, again with contracts, scopes and paying the rates to have them assume liability. It is a tough lesson learned. :) As you move forward start understanding "Thinbed " shower pans, flood testing and contracts. .

If the shower pan is built correctly, it should have a pre-slope - this is under the shower pan liner.

A pre pitch or pre slope under a shower pan liner is an essential part of a successful tile shower installation. A pre slope is the base under the shower pan liner which is pitched so that any water that manages to get into the shower base can be directed to the weep holes in the three piece drain and out of the liner.

Grout is porous. Any water the gets through the grout will drain through the weep hole (see the pebbles) they allow this water to drain.

If the pan is not constructed properly, the water can't drain. I don't know if this is your problem or not.

This might be causing the mold.

So Chris, a little bit different perspective:

I'm not discounting what's being said by Tundra at all.
I'm just not sure it matters at this point. It matters the next time you re-do this.

If you want to pull it up because you don't like the appearance - fine.

If you are ok with the discoloration, then hang with it until you re-do it.

I know this is 4 years later but the missing grout is obviously why water has leaked under the tiles. Yes floor tiles will have the odd pinhole in the grout and also as you learned grout does absorb water and moisture/water does inevitably get under the tile but a large chunk like that would increase the amount of water under ur tiles. Even with weep holes, everytime your shower water will soak under the tiles and it'll never dry off. Your base is waterproofed but it'll also increase mold etc bc it'll never really dry. What I would've done was not use the shower until everything was dry. Maybe even use a shop vac and suck out as much water as you can from that one large area. Then regrout all the areas with holes and voids. But this would've been a potential temp fix as the entire grout job could've been bad and powdering if it wasn't mixed properly.

I have mosaic floor tiles in my shower and I regret not getting larger ones because I hate all the grout lines. More grout lines means more maintenance and cleaning of it. 😑

But I do wonder how many people have shower floors that are constantly wet under the tile and not know it. I'm sure more people than not. Most people don't even realize whether or not their grout is in good shape or not.

Btw. 4 years later, what did you end up doing?

"Even with weep holes, everytime your shower water will soak under the tiles and it'll never dry off. Your base is waterproofed but it'll also increase mold etc bc it'll never really dry."

What? With a properly pitched shower pan the water will move towards the drain and will absolutely dry without any mold growing.

Unless your shower is completely water and moisture tight which most aren't bc grout is porous and most ppl don't even notice small voids or pinholes in their grout, some level of moisture will get under the tiles... Unless it's a lot of water the moisture isn't going to slide down the preslope through thinset and into the drain immediately. And if you use the shower 2 times a day, you really think it'll dry out completely? Look at the shower floor and walls, they build up mold and scum of you don't clean it every week, and those areas are exposed to fresh air and able to dry faster than moisture that's found it's way under the tiles.

It is a know fact that grout is not waterproof and allows water thru it. All of this is why the showerpan is to be waterproofed and properly sloped. This is a typical water in / water out system

I know but my point is that without any real airflow how does water or moisture that gets through the grout and under the tile evaporate and dry in a timely manner. Eventually it will, but if you take 1-3 showers a day it hardly gives it that much time to completely dry between showers. That's all I'm saying. And again, unless there's lots of water under the tile, it's not going to free fall towards the weep holes via the slope. Thinset etc will prevent it from sliding down quickly and small amount of water still will sit and very slowly go towards the drain but also be interfered with my the thinset, potentially the kerdi fibers. Etc. It doesn't just magically glide to the drain like a drop of water on a freshly waxed car.

Yes it's waterproofed so there won't be any water damage, but just because there's no water damage doesn't mean there's no mold that can grow. Mold is everywhere whether it's to the point where u can see it or not.

Millions of showers built with these methods for decades. Properly built and there is zero issues.

4 years later…yes I ended up finding out that the original contractor screwed up big time. The tile for the floor was meant for backsplashes only and not for floor tile and they just installed it without question. They also did not waterproof behind the wall tile so what happened was the water got into the backer board making it swell and grow mold. I had a different contractor redo the entire shower.

Yikes. Thanks for the update Chris but I'm glad it worked out in the end. Just curious. Did you stick with a dry back pan or did you do a system like kerdi this time around.