It is, in fact, a painting of Robert Johnson, a blues singer from the early 20th century. The legend behind Robert Johnson says that to master the guitar, he went down to the crossroads and sold his soul to the Devil.
When I think about that, all I can think about is "What a great marketer!" Claiming you had sold your soul for anything was a much more serious claim in the '20s and '30s than it is now. And he was good at playing guitar. It made it hard for his rivals to say they were better. After all, the man was in league with Satan!
What does this have to do with being a young creative? It's all about branding yourself. Give people something to associate with the good feeling your portfolio gives them.
Don't go over the top, though. Johnson claimed to have sold his soul, but he was reportedly a shy, introspective sort. His quiet demeanor added to the mystique. If he got carried away with the act though, people would have gotten tired of it.
In the end, it comes down to be getting noticed, then remembered, then liked. A director told me once that if he has to choose between casting two equally qualified people for the same role, he'll choose the one he won't mind hanging out with.