I think, for me, I always have to keep in mind, "How is this a Concern? What is the conflict here?" If being transformed into a dog means, as a consequence, you're now stuck in a cute, fuzzy body for the rest of time, then I would call that more like Universe than Psychology. On the other hand, think about the psychological aspect of being a dog: you're a pet, stuck at the bottom of the totem pole, fed scraps and kept in your kennel. Being--Playing a Role--might seem like it's external; after all, isn't it the stuff you do that makes up your role? But you need to see the psychological aspect of it: "I'm not a dog, but I need to pretend to be one for the present." Contrast that with Becoming: "Some deep, fundamental aspect of my personality is changing."
Think about what it's like to Be the President. Not the bill-signing or picture-taking or baby-kissing, but the part where you can say to yourself, "That's me. I'm the President." Or think about what it's like to pretend to be happy when your true love gets married to someone else. Not the fake smile, not the well wishes, but the portion of your brain that says, "I've got to put on a good face for them." That's Being. And when you're, say, bad at Being the President, or your cheerful facade cracks, you don't change anything external; you look inside yourself. You tweak portions of your personality, or realign your priorities.