1. Co-production: Cheng Yi and Zhang Yuxi are co-producing a movie or TV series, sharing some behind-the-scenes tidbits or promotional videos of Tik Tok. Zhang Yuxi appears in Tik Tok, Cheng Yi.

2. Personal relationship: Cheng Yi and Zhang Yuxi are good friends in private and go out to play or get together. These activities were recorded in Tik Tok, while Zhang Yuxi appeared in Cheng Yi in Tik Tok.