Is there any use for Marketh's picture?
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You get it from a father/son pair of svirfin carving a statue.

You can talk to one of the gnomes by the statue in the courtyard with all of the "shrooms. You can convince him that he is a really good artist and should pursue that as a career for a modest xp gain. However, AFAIK, that option is only available to a bard.