assigning and exporting podcast artwork

The podcast artwork that is exporting with my episodes seems to be stuck on the same one all the time. I'm not sure how to place the correct episode artwork for each new episode of my podcasts in the GarageBank window. For instance I have one GarageBand podcast project, but then I might have 8 episodes (each with different tracks) underneath. I have place new podcast artwork in the lower, editing window, but it's indicating chapters.

Is there any documentation on how to do this correctly?

Thank you,