Just checking : did you contact the artist for permission?
I am the artist, unless you mean the stock photography from sxc. In which case it isn't necessary because it is royalty free.
Standard restrictions apply and african_fi must be notified and credited when using the photo for any public work.
According to this, you must credit the original artist as well as notify her that the art was used.
Easiest way to notify her is to leave a comment on the photo page saying it was used.
EDIT: In response to this edit:
If it actually gets into the game, then the photographer should be credited and notified, not something we need to worry about right now.
It's not a good idea to take chances with copyright. The curators here are especially nitpicky on this kind of stuff, but this is for the sake of the art.
People,
You need to understand that copyrights are not to be messed with. Take every precaution when working with them as they can instantly build up into tens of thousands of dollars in fines to both you and the community (mainly zanz/SG since they are the head honchos)
You may personally ask Timerclock about the usage of art, but chances are the curators will not let this through until the artist is contacted.