Run some water and let's see what happens please.

How does it slant?

The floor tile is smaller on the right side of the tiles. The white plank is also slanted with the wall/floors. So everything is a little slanted. Contractor says because the area is slanted. The last photo shows a before picture and it doesn’t look slanted to me?

A "slant" refers to the horizontal plane and is needed to flow the water toward the drain.

I think you mean to say the floor tile pattern is not square to the wall alcove (the shower footprint is like a trapezoid, not a perfect rectangle). You can see the slivers, which he would have had to cut, and it looks like on all 4 sides (sort of, can't tell exactly), so why would you go to that trouble if not needed. Ask him where the alcove walls are out of square.

Ok thanks. Yes that’s what I meant. Was it possible for my contractor to have installed the floor tile more squared to the wall then? The white marble plank is also not straight?

It appears like the space might not have 90degree corners, and the back wall is not a single plane - it changes angle at midpoint. I can't see under the level, but the tiler may have chosen the curb to use as the hold point for lining up the tile, so the rest came out how it came out. That's why I advise to ask why the layout was chosen as such, it may help you accept it. If not, then you can pursue further discussion about who did and why the walls and footprint are not square.

I am not a professional, but I think the tile could have been laid out a lot better. He is way off on his tiling. You can see that if the whole pan could be rotated a little, it would be fine.

I took a overhead photo today!

It seems the ledge in the "before" photo could be hiding all the irregularities that appeared with the wall-to-wall re-tiling. The general contractor could have have checked for square and adjusted the walls. A larger format tile without contrasting colour grout lines would camouflage the irregularity.

If the gc had told you the existing walls were out of square and that he needed to rebuild the walls and entire waterproofing system would you have paid him the dollars for this work?

Get a tape measure.

Accurately measure the lengths of the four walls at the floor. When standing at the curb and looking at the shower floor, the back wall and front curb lengths should be equal to each other, and the left and right front-to-back lengths should be equal to each other.

Then measure the diagonals across the floor (across the drain), from the back left corner to the front right corner, and from the back right corner to the front left corner.

If those pairs of measurements match or are at least fairly close, your floor is a square or a rectangle. The tile should have been set properly.

If the pairs of wall lengths match but the diagonals are off, the floor is not square, it is taking on the shape of a rhombus.

Regardless of all that, the way your floor visually looks in the photos? The tile certainly looks askew to the pan, and it appears that the entire tile pattern could have been rotated counter-clockwise just a bit to better fit the area of the pan.

Regardless, take the measurements and see what you have.

When getting a funky pan, there are a few ways to minimize the funky. The funky can be fixed. Tile size and/or pattern can be selected to disguise the funky. The tile can be oriented to look best off of the most visible wall and the pattern played with from there. Or tiles can be removed from the mesh backing and the grout lines in the field get adjusted ever-so-slightly across the floor so the tiles fall nicely against the walls.

These things require discussion before work is done. Sadly, most of the discussions tend to occur afterwards.

No excuse for this as all four sides have cuts that angle the same direction. Simply installed slanted.

What the heck!??

Surely it would have been easier to not install it all askew!

If you're stuck with it, do get a grout that blends well with the floor tile.

It is in the early stages of swirling down the drain.