On the other hand it also seems like a rather human and heart warming practice. Is pet cryopreservation good for the image of cryonics?

Heartwarming only to people who already like the idea of cryonics, I'm guessing. To those who don't, the interpretation will probably be "selfish rich weirdos getting their dead pets frozen", which will be used circularly as further evidence that cryonics is weird and bad.