What are we looking at and take more pictures from further back.

The entire tile job is questionable. I was willing to let some of it go but I’m just sad seeing the niche.

Sloppy? I don’t know if we’re being too critical

It's not quality workmanship. You also chose dark grout which really accentuates it. If people "must" choose the trendy dark grout with light subway tile, they need to realize the importance of hiring a qualified tile contractor. For that matter, showers are not for the amateurs, period. If the workmanship is this visibly poor, we can only hope the most important part of the job (the prep underneath it) is not as poor. Read this about tile layout: https://www.ceramictilefoundation.org/blog/tile-layout-centered-balanced-no-small-cuts?utm_campaign=tile%20certification&utm_medium=email&_hsmi=214400661&_hsenc=p2ANqtz-8xH6aBhKCi-1VKNuDQTciOEhlGFS2qj3UJ-plF5DDF5zru1KqE0YKD5hP6XZPDEtNKAgnJupscGiE4M21Bj7SQOYBhoA&utm_content=214400661&utm_source=hs_email

Most importantly, how did they waterproof the shower?

Yes they did

Are these tile slivers acceptable?

Here’s some
Photos that show the waterproofing

Just a note, the floor tile install was done by someone else and we are really happy with it

What waterproofing???

I would not want slivers that tiny, but the bigger issue, IMO, is that they aren't consistent. We do have slivers in a 3x6 running bond subway layout, but the tilesetter figured out what the shortest sliver needed to be based on how square (or in our case, not) the wall was, and then kept that consistent along the outside walls, adjusting the inside tiles to absorb the fact that the walls are way out of plumb. (He had to pick up nearly 2" from bottom to top on one wall, and 1" on the other.) On one wall the sliver it is consistently 1/2" on the outside edge--the smallest I would personally want--and on the other the sliver is consistently 1". Meanwhile, the tiles that meet on the inside corners slowly increase up the wall to account for the lean of the wall.

In yours, I'd guess that they started at the bottom with whole and half tiles, but by the time they got to the middle, the wall was not square and the sliver was needed to cover it. They should have checked before doing the tile layout.

Are these pictures not decent waterproofing? It’s some sort of board and then a membrane painted??

The shower was glasroc and then painted with this blue membrane

@Steve Hiklar, You ask if the slivers are acceptable? No. Did you read the link I attached above regarding layout? That is the professional explanation about layout and "slivers".

thanks Dragonfly. I did read it. We’re beyond disappointed. The job looks so amateur and the more I go stare at it, the worse it gets. We’re on the fence here trying to decide how to proceed. I don’t think these guys have the ability to do a good job. I should note they contracted out the floor tile to a tile guy that did a fabulous job but didn’t have time to do the shower. They cut corners and did that part of the job themselves.

So there you go. "They did that part of the job themselves". Not professional tile installers. Obviously.

The upside is that they already work with a tile guy whose work you are happy with. I'd just tell them this is unacceptable and they need to have the tile guy come and redo the work properly.

The cuts on the tile remind me of our kitchen backsplash, which we DIYed. We got a tile saw from our local library, and discovered after half a day that we needed to go buy it new blades--but unfortunately we'd already cut more bullnose tiles than we had spares, so some are still there with their jaggedy cuts many years later. But that was free, and also the first time we'd ever tried it--if I'd paid someone to do it, I'd expect them to know to have a proper blade and to cut the tile cleanly.