None of it is ok.
None of it, actual assault or words alluding to it, making a joke of it.
I have a background in art and so I guess I see visual culture very astutely around us in the way it permeates society, from a decorative item to a significant meaning with links to attitudes that breed actual assault. We are visual beings who have 'tribes' defined by how we visually present our selves. And in this day and age, that's with our FB, our twitter and our t shirts.
'We' (some of us, general populace) are also gullible beings who become conditioned to believe what we see and experience as being acceptable as it's in mainstream media. And media is also a t shirt, given the way we wear our brands.
So, actually, it matters in a lower scale in terms of offence and actual harm but it still matters in my honest opinion, as it is how it could be interpreted, who might see it and who may repeat it and translate it into actual attitudes.