It's actually a bir more then that.

They will usually remove the bedspread and fold it away somewhere so they don't have to pick it up off the floor in the morning

They will fold down the sheets, and put out the extra pillows.

They usually leave a chocolate or a mint on the pillows

They will usually replace any towels you have used, or at least refold them at the same time.

I'll never ask for it when I'm in a hotel, but if I'm out and they do it it's sort of nice to come back to a room all ready for bed.