What does Tik Tok's poster mean?

Tik Tok's placard means holding a written sign and taking pictures. Source of placard: from cos circle. Used to verify my identity and make sure I'm not a scam. Someone will take a picture of a brand with his name on it.

Later, it was also used for commercial purposes. Coser or a designated person puts up a sign and writes down some specific words, such as blessing words, love words and confession words, which are very popular in Tik Tok.