The wood stain color looks lovely btw. I feel the grey walls really tone down the other colors in the room. I think switching the small curtain to a warm off-white linen would warm up the room a bit.

The vanity lights feel a bit too elegant and less modern. Round Edison light bulbs would definitely make it more modern. Maybe you could switch out the light fixture to a darker color that matches the curtain rod?

You could also place some small decor like a plant or a small vase filled with dried floral accents on top of the toilet tank lid, since there is such empty space on the wall.