I don't see a shift in pattern. I see two shades of grout though. It could just be efflorescence. The two little black tiles are positioned where they should be according to the pattern, with 7 white hex's in between each black flower.

I think it looks fine. If the singleton black pieces bother you by the tub, it would look ok replacing them with white in those spots.

I don't think it is grouted yet.

Walls in homes are almost never plumb. Sometimes, a tiler can make small shifts in the tile to make up for the crooked wall - but that can also mess up the grout lines, and a hex tile can be difficult to install and keep the grout lines uniform. Your grout lines look like they will be pretty uniform. I think this is good install - I don't know if the pattern to the left could have been improved by tweaking - as I said, that can mess with grout lines, but I think once it is grouted and the walls tiled or baseboard applied, the slight crookedness of the wall will not be noticeable.

Use a light grout and you will not see any imperfections with spacing. Install looks good. I would remove the 2 black dots along the right wall to give the illusion that the wall is straighter and the room is square.

You're right, jhmarie. I thought I was looking at dark grout with white tile (I keep seeing it everywhere!).

Seems at the first view/step into the room he placed 2 black sets centered. Is that right?

White grout will hide grout spacing imperfections. If you're super picky you will not like the aftermath of a darker grout used with this install.
In the photos I see several spacing imperfections.

It's nice and the 1 black could be changed to white [by the tub]? Was the floor prepared and level.... you'll enjoy it when it's done! :)