About the Satan spawn, my guess is it's just what happens sometimes. Eyes can be very reflective and so sometimes glow in photos.
The little girls eyes glow much more and a reason for that could be that the house is dark. There seems to be no light sources from the rooms inside the open doors. That means the girls eyes are adjusted to the dark with expanded pupils that would "glow" even more when there's a sudden flash photography.
Looking at the shadow, it could look as if all the light in the room comes from the flash, but I don't know that for sure, obviously. Like the Tombstone pic is strange as it doesn't center the man, this one seems a strange picture to take if you didn't expect anyone to be in it.
A fun thing about those two pictures is that they simply look like people. At least the tombstone man looks like he might be coming out of the ground, but anyone could just take a picture of people and claim they were alone when they took the picture.