Creepy, possessed little girl with a bag over her head
Imdb cleans out posts when those get too old. Back in 2009 and 2010 there was some back-and-forth discussion on the creepy little possessed girl with the bag over her head, grunting and growling ominously as she banged a long stick on the hood of a car that the desert diner survivors were trying to drive away.
There was no explanation in the movie but a plausible one exists on the Q & A board. The explanation is that normal human beings were being possessed while doing normal daily activities. The little girl may have been involved in a, break-the-pinata game, which might account for the bag over her head and the long stick she still carried. That sounds reasonable enough to me.
It sounds more plausible that the explanaton I invented. My theory back in late 2009 (now vanished off imdb) was that the little girl was possessed by a higher-ranking angel and possibly her face was damaged during or after the possession. Possibly the angel felt the need to conceal its human little girl face for some unexplained reason. The horde of possessed humans were temporarily frozen while the holy baby was in their midst. But the little girl was only partially...more like, held back as a vampire before a cross. The possessed little girl could still move about and vocalize but was held back by the presence of the holy baby. We movie-goers at the time in the theater expected the little girl to try to attack the fleeing human survivors, or try to rally the temporarily immobilized possessed humans. This was a red herring the director threw at the audience to scare us.