I’m not sure how these children relate to the grumps in this photo from last week, But they seem to share a venue and photographer. It’s the same (or very similar) venue, a folded sheet of some sort hung as a backdrop, with a dirt floor. The kids’ footing is improved by adding a reed mat on the ground for this photo, but it didn’t improve the children’s attitudes. Little Gunther looks like he’s about to cry, and the photographer is lucky Marta can’t actually start fires with her mind even though she’s trying really, really hard.
The style of dress is of a similar period as the previous photo, but a bit more formal: all white may signify some religious event is taking place (baptism, first communion, etc.), or it could be that their church-clothes are the nicest outfits they have to put on for a photographer.