I never heard of anyone being able to pull this out on a daily basis. One, here, one there, will do, but nor everyday. There are multiple reasons and it's a long
story.
The main issue is that you need to be in the listing agreement. You wont be in any listing agreement! If you are not in the listing agreement, you are not paid through the escrow. If you are not paid through escrow, means the listing agent has to pay you directly, but after the home sells.
Now, that's exactly as being paid at delivery, but with the risk of not being paid. Will you want to do that?
Who is gonna track the whole thing? Imagine 15 homes a week... track them over the coming weeks and months, follow up with the escrow for sale price, calculate your fees and invoice, then wait...
I have been in RE Photography for years. It takes effort and logistics to bill every job in clear, once you delivered. Add the variable "if it sells" to the mix and it's becoming an ordeal.
Try it but don't expect much...