The Girl in the painting doesn't think she's unreliable; she pushes others aside and strides up to Yan Jiayu, raising her hand high.
"What are you doing!" Qi Cong is a bit agitated, "Little Yu'er is already hurt, and you still want to hit her?"
The Girl in the painting doesn't waste words with him, she backhands him, sending him flying, and then lifts Yan Jiayu, slapping her kangaroo-like head repeatedly.
The others also wanted to see if it really could awaken someone, so they didn't try to stop her.
Yan Jiayu woke up, but not from being hit. She had a brief lapse of consciousness when injured by the "Sealing Door," losing her primary awareness and nearly being assimilated by the prop. When she was pulled from the wall, she couldn't move, but her mind had started functioning again.
"Stop hitting." Her mouth recovered faster than her limbs, she stopped the Girl in the painting, saying with some helplessness, "I'm inside the prop; if you hit me, I won't feel any pain."
