Board Thread:General Discussion/@comment-26198832-20150313123438/@comment-25464947-20150320035226

" There was no stating that Rose and Blue Diamonds were actually giants while fighting. In "Tiger Millionaire", Ameythest maintained her form as the Purple Puma despite being caught by surprise and getting emotional when the other gems appeared toward the end of the episode."

Whoops, bad phrasing on my part. I never thought that Rose and Blue Diamond were actually giants, the main point of the first half of my post was to explain why that was probably not the case. I added the part about shapeshifting later to answer AMO's question.

Based on what we've seen so far, I think it takes more concentration for gems to change forms than to maintain them. This would explain why Amethyst had trouble shapeshifting out of Garnet's hand but could take a beating while already in her Purple Puma form.