The Nuances of Speech
Just so you know, I wholeheartedly agree with the sentiments of this picture - but that's not actually why I put it up. I put it up because today on Twitter someone said it was hate speech.
Short answer: No it's not.
Long answer: No it's not, because this picture is not seriously advocating killing the Queen and could not seriously be taken as an incitement to violence. Neither is it racist, sexist, ableist, homophobic, transphobic, etc. in any way whatsoever. It's dark humour. It's not meant to be taken seriously. It's the equivalent of saying "I'm going to fucking kill [X] when he/she/ze gets home" in frustration; nobody seriously expects the speaker to grab a chainsaw and attempt to murder [X]. The same thing applies to the written word. And it's pretty damn different from actual hate speech, which still seems to get a freer pass than it should.