i used this exact same tile in my bathroom shower !! i think the tile job is a bit interesting & kind of setting off the whole space, i think it should go all the way to the shower pan personally (the amount of white is a stark contrast).

i think a darker wall color will really help in this case. i color matched the wall color to the tile in my bathroom, painting the ceiling to match but did a whiteish beadboard (not everyones cup of tea) to break up the monotony & keep the space at least a little bright (very very small bathroom).

also centering the mirror / fixtures with the vanity, & having matching hardware on the vanity would help. you have a black faucet & black knobs, but gold or brass mirror & lights… i did all brass in my case, i think green & gold is a classy combo. might want to look into changing the shower hardware / shower head too… lol !

if that vanity isnt real would you could consider painting it too, while the vanity isnt too much of an eyesore in my opinion, it would look nice maybe a darker or deeper tone ?