Playful sexuality, I assume. Following the clothing fashions. Thinking that it's a nice picture of a rabbit. Or, following the side of my brain that doesn't think about these things very much, possibly advertising availability. But on children's clothing?
I've admitted that my instinctive reaction to seeing people wearing this trademark is disbelief. That the signal I pick up from people wearing it is "I'm an idiot who doesn't think about what I'm wearing". This might not be fair - the people wearing it might have given it considerable thought, be sending out some signal I'm not culturally equipped to understand. Maybe I'm just bigoted, uncomfortable with my sexuality or something. Incapable of understanding the cultural mores, getting old and railing against the youth of today and their parental rebellion.
But even so, I can't shake the belief that one way or the other, they're idiots.
 Musings which are not fully formed and thus probably not correct - but which I'm inflicting on the world incomplete anyway. Feel free to attempt to realign my thoughts.