Make sure the corners and all changes of plane are 100% silicone caulk, never grout.

Move on.

Move on.

Move on.

May I ask what color grout you are planning for your floor? I love your tile choices.

The accent tile is not linear in any way, so my eye was not looking for the strong horizontal on the sides to match anything. I don't think anyone would ever perceive it without being explicitly told to look.

You’ve got much bigger problems than that. Greenboard is not a waterproof base for tiles.

Good catch, clt3.

A color matched solid surface cove molding in the corner may throw off your eye. This is the fault of the person who selected the tile, not the tilesetter.

The niche tile not being lined up would bug

You choice of different tile sizes means that the grout lines won't line up. However, it looks like greenboard is being used in the shower and the joints have not been taped and thinset applied so that's your cue to rip everything out and use better materials.

You could have laid the 12x24 tile in a vertical direction.

If that is greenboard then you're looking at redoing the whole shower in a year or two because it's not waterproofed.

IMO the patterend tile was a bad choice for a shower wall and the fact you bougt 2 different sized tiles and wanted them to line up was on you IMO he did the best he could with the materila provided I also agree that waterproofing is not right so maybe a good time to rip it out get a better tile guy who understands waterproofing and choose different tiles . IMO bathrooms are best when done in a min . of tile styles an sizes I like 12 x24 porcelain tile for both bathoom floors and shower walls I hate niches they always look messy and why anyone wants shampoo bottles as decor is a mystery to me .3 styles of tile in a tiny shower was just bad choices .

This was a designer who chose the tile
online they both say 8 inches high
I would think the tile guy would measure them and call out issues before installing it.
The GC says the material is Durock
The niche is not center and it drives me insane- they said it was because a “stud was in the way”… the tile guy said he centered the pattern anyway.
We aren’t happy but it’s a tough conversation so far

https://www.usg.com/content/usgcom/en/resource-center/faqs/564.html

Waiting to read comments on waterproof membrane….or lack thereof.

Durock per the OP and the green is most likely Aquadefense waterproofing.

I think the grout lines is a non-issue that no one will ever notice, since the grout lines in the pattern tile are not strongly linear, as someone mentioned, if you grout the subway to match the tile instead of contrast, it will look fine. I would ask the tiler to tile the back of the niche (over the top of the patterned tile so as to not ruin the waterproofing by removing it) with the penny tile from the floor. That will fix the off-center problem and will look nice, I think.

"I would think the tile guy would measure them and call out issues before installing it."

Prolly be the last time he worked for that designer. Many don't appreciate second-guessing, particularly by lowly tradespersons.