As a customer, I check the Product Showcase almost everytime I check in here. If I want to see what's available for sale, I look in the Marketplace or the Product Showcase.

If an artist wants to display their work they should be able to do that. If the artist happens to be a merchant they should still be able to post their artwork in the appropriate gallery like everyone else. If I see an image in a gallery that's by a merchant and it has a list of credits that say "This by me", "That by me", "The Other Thing by me" then that looks like a promo to me and promo images belong in the Product showcase. If they want to leave off the credits, that elimates the promotional aspect and that image should be allowed in any gallery.

Art by a merchant for expression is art, art by a merchant calling attention to that merchants products is a promotion.

That's my 2 cents.