Yes—an artifact like this can happen if there was camera movement during capture or a sudden strong change in light. Phone cameras often combine multiple frames for HDR and stabilization, so motion or changing light can produce odd blended artifacts.

Based on the answers provided, this kind of white blob would not normally appear “from nothing” in a stable, unchanged scene. It is more likely tied to movement during the shot, lighting changes, or both. If it happened only once and you can’t reproduce it, there usually isn’t much more to diagnose from a single example.

So the most reasonable explanation is a one-off capture/processing artifact rather than a persistent hardware fault.