I'm probably gonna get some hate mail on this, but, IMHO, the real question here is:

Is it art or is it just a political statement. The two are not always mutually inclusive. Once could certainly say it's creative to some degree, but is creativity all that qualifies something as art?

A 2 year old dips it's fingers in paint and swirls them around on a page...the child is being creative, but is the result art?

An elephant at a well known zoo holds a brush in it's trunk and splashes paint across a canvas. The paintings sell for thousands of dollars. Is it creative or just a learned response to a command from it's trainer and is the result art?

So, my real point in all this is, if this image is really only a political statement (which in my humble opinion is all it is), does it really belong in the galleries, which are there presumably to display art. If in fact it is not art and is only a political statement...it is irrelevant whether or not it is offensive, and what is relevant is whether it ought to be in the galleries at all. Perhaps the appropriate place for an image that is simply a political statement is as an image attached to a post in The DEN.