It looks like Kat knows Art (and JJ) all too well! Still, she does have a point. A subscription-only NSFW art is probably a bad idea for a card to send to grandma... depending on the grandma, of course. Some would appreciate it, I guess!
Now, was it me or was Kat volunteering to be a model for this piece? She does seem to have a slight exhibitionist streak which, given that she's a cat-anthro, shouldn't be that surprising!