Seemingly cute, no doubt. But the astute observer will notice much more happening here, beneath the surface.
For example, most people would imagine that the bulk of the humor in this photo is connected to the mouse. But a trained eye like mine would never make such a brash and incorrect assumption. The humor, in fact, lies almost entirely with the bunny.
Look carefully at this bunny. He is troubled. He doesn't fit in with the other three animals, and he knows it. The other animals are probably less than a year old. The bunny, however, seems to be about 40, and has a melancholy look in his eye, as if he's not sure where the years have gone. In body, he's on sitting there with the others, but his mind is elsewhere. He's made some decisions he regrets, and lately, he's been wondering, more and more, "What's the point?". This is certainly not where he pictured himself at 40, being photographed in an amusing photo with three children. No, things have not turned out the way the bunny planned. And that is simply something that he will have to accept.
Others may see 4 cute little animals. I see 3 cute little animals and one troubled, middle-aged animal in crisis.