No

I think it adds interest to the neutral cabinets and countertops. If you like mosaic tiles, go for it!

Not sure if I’m a fan of mosaics

I like it. (although, i'm seeing a pattern in the layout w/the darker pieces. did you randomly select a sheet from different boxes or did you use all of one box, and then go onto the next box? if so, you'll get patterns because each box of sheets will be slightly different. )

hate the yellow walls. (which really throws off the look of everything at the moment)

I'd grout w/a neutral gray grout.

I would have tiled above the window and done a little sconce.

I also would have done a simpler window trim molding that matches your cabinets.

or like this window:

Thank you Beth. That was the idea, to extend the tile up to ceiling. Yes, installer just opened one box, moved to next box. I too see patterns. I too thought of a sconce but a trio of pendants is going 3 feet in front so I feared overkill with lights. Like your suggestion with trim. Thanks!