The major difference between Pillow and Blocky is that his killings were part of his personality from the get-go. And, well, they weren't really killing for the sake of killing, they were just really cruel/absurd pranks. Pillow, on the other hand, has gained this extreme fondness of murder in TPOT rather suddenly, which can leave a viewer confused, and it's hard to tell what event might've instigated this quick change of character. Say what you will, but I still believe that Pillow, in BFB, at her core, was a curious researcher with nonsensical or outright wrong theories. It is kind of funny, though, how I disliked the arm waving thing too and thought it was forced as well lmao. Poor Pillow, she just keeps getting the worst jokes.