Yes the character design did seem familiar as well.
The girl (Lucy) from "Pandas Date" reminded me of Beatrice from Over the Garden Wall.
Seemingly others have spotted a Dipper from Gravity Falls on the episode "Chloe"

I feel like such an idiot! No wonder why Garnet has that one eye at the top since Saphire has one eye aswell in which she has future vision. It's surprising that both Ruby and Saphire both have their own element. Are they the only gems with elements??
Anyways this episode was very cute! Everyone wanted to see more…