It was suggested at https://chatlogs.metabrainz.org/libera/metabrainz/2024-06-03/?msg=5343736&page=3 that we should have a relationship type to link artists to events they created the artwork (e.g., poster) for.

Ideally we'd be able to link the artist to specific pieces of event art, in case there are multiple pieces of artwork by different artists, but I'm not sure how we'd do that outside of abusing a free text field.