Plenty of light is always ideal in bathrooms, but it can draw negative visual attention to tile lippage on walls. I'm sure this was a very tough installation. Look at the natural light washing down the wall! The TCNA recommends that bathrooms have no ceiling lighting within 24 inches of a wall and no lighting on the wall, if possible. Light that's so close to the wall can exaggerate the visual lippage on the tile and make even properly installed tiles look poorly installed. Obviously this lighting recommendation can be hard to follow, so it's just an aesthetic recommendation. Tip: If you have wall-washing lights or wall lights, get these installed before tiling. If the bathroom lighting includes a new skylight, unwrap it before selecting your tile so you can see how the tile will look in the natural light.Lippage is most noticeable under the cabinets in kitchens when the electrician installs undercounter lighting after the tile is installed. Get those lights installed first!