Of course the way you express this depends on the social circumstances, the country or city, and even the nuance and language of each party.
While it is difficult to answer correctly for all situations, I have thought hard a bout this issue. It certainly also be of great concern to you, or you would not be asking the question.
So, after consideration, I think this is the best way to say I wait for your photos?
"Hello, I am waiting for your photos."