A Pooshee is neither an insult or a compliment. But it can also be both, or one of the two. It depends what the person saying the word has for an intent.
A pasty white fuck. Usually associated with unatheleticism, creepiness, lack of humor, and social akwardness. His lack of friends leads to a shut in life of video games (gay ones) and following "cool" people on weekends to find parties.
The fattest and laziest cat you'll see, eats more then I do if I had tapeworm, sleeps more then I do on vacation. He's so cute and adorable you want to squeeze him so hard his organs explode out of his anus.
You:pusheens so cute
*squeeze**explosion sounds*
You:cry because you killed the cutest cat in the world.