Board Thread:General Discussion/@comment-26335243-20150415213014

As you may know, in the episode "So many birthdays", there is a painting that depicts the Crystal Gems many years ago (exactly how many years is unknown) before any Steven Universe episodes took place. In this painting Amethyst resembles her current form in the series, however, in the episode "Story for Steven" Amethyst more closely resembles a child. My theory is that like in the episode "So many birthdays" when Steven progressively gets older, gem's ages can fluctuate based on their state of mind. After the events in the painting occured the gems didn't go on many missions allowing them time to relax. This made Amethyst feel like a kid again and her mindset was then reflected on her physical form causing her to look like a kid as well. Many years later when Greg "crashed his van into their lives", Rose "died", and Steven was born, Amethyst was forced to mature and adapt to the situation thus causing her to return to her current form in the series. 