Why do humans find baby animals cute?
In German we call it "Kindchenschema" which is unfortunately translated only to the more unspecific "Cuteness", but sometimes also to "baby schema". This seems to be applying to most (care taking) mammals, also over species borders. The specific looks release hormones in the adult triggering care taking behaviour. This is to ensure the babies safety. That it not only works with the own parents helps ensuring the baby is cared for even if the parents cannot do it themselves.
Interestingly, the head and eye shape seems to trigger this hormone release. And it is the same for many animals. Like always, evolution uses the same winning scheme over and over again. This is why you can get a dog to care for abandoned kittens, and why you will find those puppies ever so cute.