I am glad you brought this up. When I joined here 2 years ago i passed on this as I was uncertain of the terms. I am also exclusive for royalty free licensing. This appears to be an RM license from the little bit of information that they give. It seems the license is only for the purpose of having the art in that specific use. I have changed my mind and opted in on this. It is not a sale or a contract so just opting in does not violate my exclusive agreement. The chance that this would be an RF rights grab is rather remote. If it is I just would back out or contact my stock agency for advice.