In the song sequence at the beginning of Steven Universe Future we see this picture:
What is it? It definitely isn't composed of scenes from the four episodes in the set. Is it a sort of montage of villains from the past episodes? The presence of Jasper and Aquamarine might suggest that, as does the tall figure who looks rather like White Diamond. That said, I don't remember her being so magenta or angry, and I am at a loss with regard to multi-headed cactus Steven and twin Lapis Lazulis.