Repair what looks neglected
Soft flooring at the tub, stained grout, a caulk joint that has pulled away, and a fan that does not actually move air tell a buyer the wet areas have been ignored. Fix those before you spend money on a new mirror. A clean, dry, ordinary bath beats a styled one with a soft subfloor.
Waterproof the wet walls
If the tile is coming off or the shower has been leaking, this is the work that matters. A proper shower pan, sound backer, and a drain that sits where water goes are what keep the next owner from inheriting your tear-out. Cosmetic tile over a failed pan does not survive a resale inspection.
Light, air, and fixtures that work
A bath that is dim, steamy, or fitted with a faucet you have to fight will feel older than the rest of the house. Recessed or vanity lighting that reaches the mirror, a fan vented outside, and fixtures you can still get parts for are enough. Matching metal finishes across the faucet, shower, and towel bars makes a small room look finished.
Floors that belong in a wet room
Cracked tile and swollen vinyl are the floors buyers step on first. Porcelain tile and a waterproof luxury vinyl are both reasonable here. Large-format tile can make a small bath feel calmer if the layout is simple. Heated floors are a comfort, not a requirement for a Houston sale.
If you are selling soon, skip moving walls and adding a second shower head you do not have the water heater for. Spend the budget on waterproofing, a sound floor, and fixtures that look intentional.