Hey there,
Your question/statement reads: Jonathan is a photographer. he has been hired by a company to shoot an advertisement for their product. which role does Jonathan play in the advertising process for the product.
Based on the small excerpt above, I believe the Jonathan would be played as the (boss) in a way. It said on how he advertised and he also hired people. So he would be the (boss/leader) of this. And also, he would be the owner of this product.
Hope this helps.
~Jurgen
