The first picture is terrible. There's no perspective. The reflection makes it even worse. It's impossible to tell what one is looking at.

The first pic is the tile sitting on the bathroom countertop

A little to much going on with the sink counter, wall and niche. As for vertical vs. horizontal go with what you like since the room size is big enough for either.

love the horizontal. looks neat and spa like. love the stones.

I wouldn't do that marble-look tile with the vanity top. They are fighting each other. I'd select a simple white or gray tile with the vanity, or a simple white or gray vanity with the tile.

I did vertical in the shower and think it came out great. Is the tile going to be in the shower or on the walls?

I like the vertical placement, but I don't like the mix of those tiles and that counter top. Your countertop is very busy, and either tiles (the faux-marble, or the white and gray pattern) will make the area look overwhelming, IMO.

The vertical placement is more modern and the horizontal, more timeless. Emily Henderson had a good article on her blog about this recently. May want to check it out!

I would go with horizontal install because it will carry the same direction of the veins in your countertop, adding consistency and repetition to your space. I think it will look more cohesive than a perpendicular break in the design. That is if I am reading the photo correctly. Good luck!

busy, busy, busy - go plain white.

Keep the floor tile, change the rest.

The new cabinets will be white, the new floor is wood tile planks. i am changing the shower floor from the white/grey flower-like pattern to a white with grey grout. my husband is hoping the counter tops don't make the transition from the top of the old cabinets to the new cabinets (previous owners put lipstick on pig by replacing ALL countertops but leaving old cabinets). If the bathroom countertops break i am changing them to something simpler because they are busy for my taste. if they make it, we may swap later on.
the good thing is not nearly as much will be visible. we are shortening my husband's vanity a few inches to expand shower and my side is having uppers added. example photo attached, we saw this at the tile shop and loved the look.

We agree, go plain white. The patterns are competing with one another.

A fun rule about lines: horizontal lines are peaceful, vertical are energizing, diagonal are "fun!" (if not chaotic). With the space you have, it might just be about the feel you're trying to achieve rather than ceiling height, etc.