What is objectionable about this comic strip?

My local newspaper The Plain Dealer today had this statement in place of the normal Non Sequitur comic strip, one of my favorites.

Editor’s note: Today’s “Non Sequitur” strip was withheld because it was deemed objectionable by Plain Dealer editors. A replacement strip was unavailable at press time.

I naturally went on the web to see what was so shocking and am frankly baffled. Can anyone tell me why this strip should have been withheld?