I have been informed: "For most of these reliefs, it is the goddess Cybele (lions, tambourine). There is a very big difference between Cybele and Artemis, they are two distinct goddesses. But there is a strong connection between Cybele and Artemis of Ephesus. "

Elsewhere it is described that Artemis transformed from Cybele, and would be shown with the lions belonging to Cybele. I wish I had more information.