There have been many people that have said that a variety of things allow us to judge people, (and not in the negative sense necessarily,) from the way he eats gummy bears, to well, lots of things. Besides the fact that this picture is absolutely adorable, I think that the quote from Kant here is actually one of these statements that holds the most truth. You often hear how, according to the FBI, most serial killers and rapists started out with abusing and killing animals. Stories with a villain often tell you things about their past like they liked hurting puppies as a child. It is in fact, very revealing of one's character. Once you have developed a callous towards the suffering and treatment of animals, it is not hard to develop one towards that of humans. So, think about it, and notice people.
