Stella runs a traveling Pokémon circus that set up camp near Pallet Town. Her act's main attraction was supposed to be Mr. Mime—until the performance Pokémon basically went on strike, refusing to leave its trailer and spending all day eating. By the time Ash met her, Mr. Mime had gotten pretty overweight.
What you see is what you get with Stella's public persona: she comes across as genuinely nice. But behind the scenes? Her training is brutal. When Ash volunteered to fill in as Mr. Mime during a show, he got the full treatment—whipping, screaming, the works. He was actually pretty sympathetic to Mr. Mime's burnout after that, saying he wouldn't have shown up to work either if that's how his boss treated him.
Eventually Stella had a moment of clarity. She realized she'd been pushing her Pokémon way too hard and apologized to Mr. Mime. It forgave her, and the two got back to working together at the circus.
Content compiled by AnimeList.moe from publicly available sources.
