Even though there is nothing unreasonable about asking the Stewart to clean my room next,, or at least soon, I have to understand that maybe several other guests have asked the same thing. Which could be the reason for a "no, unfortunately I can't do that".
I use the red/green "signals" a lot and most of the time my room is done at a good time for me. Not that there is much to do there so it's no big deal if I come back to it and it's not done yet.