An empty house shows everything. Without furniture and rugs, the scuffs, dust lines, and grime that were hidden for years are suddenly in plain sight, and that's exactly what a landlord, buyer, or listing photographer will notice first.
A proper move-out clean covers the inside of every cabinet, drawer, and closet; the inside of the oven, refrigerator, and microwave; baseboards, doors, and light switches; window tracks and sills; and bathrooms scrubbed down to the grout.
For renters, this is often the difference between getting a deposit back and losing part of it. For sellers, a clean, bright home photographs better and shows better, which matters most in the first weeks on the market.
Book the clean for after the movers leave, and if a realtor is involved, coordinate access through them. A good cleaning company can work from a lockbox so you don't have to be there.