Who is the person in the picture frame in Cartman’s house in the first episode?

I was rewatching Cartman Gets an Anal Probe, and I noticed something I never paid attention to before. There’s a framed photo on the side table in Cartman’s living room. It’s a picture of a random girl — she’s smiling, and it looks like a school portrait.

Does anyone know who this is supposed to be? Is it just a placeholder image, or was it someone involved in the production? It feels way too realistic compared to everything else in the show. Curious if this has ever been explained or if anyone else has theories.