Sometimes, usually in TV shows, it might happen that an actor is shown via photograph or a prop of their body. They themselves don't make an appearance, and don't do any voice acting.
For example, in a Grimm episode from the end of the fourth season, a box is delivered to Nick Burkhardt containing:
his mother's head. But there are no other scenes involving her in that episode, IIRC.
In another show (I don't remember which), a good deal of time is spent chasing someone, based on a photograph, which was shown repeatedly on screen. When they do finally catch up, the someone turns out to be a different person. I don't recall the details - whether it was a case of stolen identity, or appearance-altering tech or powers.
In such cases, does the actor involved get screen credit? Or do they just license the right to use their likeness?