On the surface, this seems to make perfect sense. The part that most people don't seem to understand is that real estate photography companies hiring photographers are very sensitive about the photographer quitting and becoming a competitor. So most will want you to sign an agreement where you agree that you won't compete with them (a non-compete agreement) in the future.
It turns out non-compete agreements are a huge problem for workers all over the world. A recent article in the New York Times says:
A recent survey showed that one in five American workers is bound by a non-compete clause. They cover workers up and down the economic spectrum, from executives to hairdressers. Despite their widespread use, these agreements often catch departing workers off guard because they are rarely highlighted during interviews and are usually tucked inside employment contracts that are full of impenetrable legalese few people can understand.
Laws in some states, like California, make non-compete agreements effectively unenforceable while other states like Idaho make it easy for companies to enforce non-compete agreements.
So, if you are going to work for another company:
Better yet, build your own company and work for yourself so you have complete flexibility. It really isn't as hard as you might think!