Even with a full width mirror, because of the light fixture placement, it still looks off to me. I would use a LED lighted mirror and forego the light fixture above the mirror. If you need more lighting I would use can lights in the ceiling. https://fleurco.com/furnishing/halo https://fleurco.com/furnishing/sunrize

IMO two mirrors would look best. Have you considered round mirrors? They're quite charming for double sinks. This page has some great round mirror ideas. You have a gorgeous bathroom by the way, very charming and bright!

Okay, so I'm not a professional or anything, so keep that in mind, in case I make an idiot of myself, lol. What do you think of matching framed mirrors over the sinks, and then a second set of matching framed mirrors (different than the first set, but coordinating with them) for the makeup area? The pattern along the wall, from left to right, would be A-B-B-A. My first thought would be visually heavier mirrors for "A," and visually lighter/softer mirrors for "B." I'd keep the light fixtures all the same, for continuity, either by using pendants or (like you mentioned) 3-lights on the short walls and 5- or 7-lights on the long wall, from the same line. Am I crazy??? lol Edited to add: So, I'm lying there, nursing the baby, and this voice inside (that sounds a lot like my husband) is telling me that my idea here is totally Classic ODD -- Unnecessarily complicating things. :-/ I think I'd pick 4 identical mirrors, and place 4 identical 3-light fixtures over them. Do you think you'd have weird strips of wall between some mirrors, with that arrangement?

I would use a large mirror across the whole space, remove the medicine cabinet, and use two side sconces and lighting above the mirror. The space isn't really large enough for two mirrors. With a new vanity you may have better storage and not need the medicine cabinet. To me, the shower tile doesn't work well with the shower floor or the bathroom floors. I'd use a solid white tile for the shower walls, which would be brighter than your floors and look good with the small blue tiles.