What is very intriguing is that the flash was not used when taking this picture. Thus, it is dark, but the orb is very bright - producing its own light:
"I took these pictures in a slate mine which is over a 100 years old, in the Lake district - England. I did not use a flash, but when I came to download them, I noticed this orange light and a couple of orbs. The orb on the right seems very bright, considering I didn't use a flash. You can make what you like of it, but I see a figure pointing and another figure further behind in the background."