I'm glad that Slater has the balls to do posters for all types of artists without fear of what other people will think of him (or at least it appears that way to me). You can reach a larger audience by doing this. Like me, for instance. And Lady Gaga may not seem unique to some people, but she's had hit after hit and has written songs for other artists too.
I predict a record-breaking number of "Love the poster, HATE the artist" comments, because I have made a Herculean effort to never make one myself -- but it was all I could think when I saw the thumbnail.