Ever paused a show to ask “wait, who is that again?” Googling a character mid-season is a minefield: search results, IMDb cast lists, and wiki pages happily reveal deaths, betrayals, and late-season arrivals. Who’s That? shows you every character’s face, name, and the actor who plays them — and nothing else.
Watching a TV series? The spoiler shield only shows characters who have appeared up to your season and episode, so nothing from later in the story is ever revealed.