Joseph has two different words for "spin." One, pronounced "pin," refers to when he, himself, is spinning. The other I haven't yet figured out how to transcribe, but it has two syllables and refers to spinning an object, like a top, a ball, a block, a coin. Whether it's supposed to be one word, or a two-word command, the meaning is clear when he hands you an object: "Spin it!" You'd be surprised at how many items that are not tops can be made to spin.
"Pin," on the other hand, can refer to being spun in someone's arms, or twirling himself around till he staggers with dizziness, or being spun on Mommy's office chair. When he does the last sitting backwards and holding on to the seat back, it can be very fast, and produces an impressive postrotatory nystagmus.
He also likes this, sitting in his space capsule (backpack) and training for NASA. The position makes up for the reduced rotational velocity. At the end he is saying and signing, "more."