I have looked at the picture closely, it is certainly intriguing. It would be lovely if it was energy or fairies but I think, having studied the dimensions, that it's much simpler.
The first shot has captured the reflection of an object on the fence, or even a bottle in the field behind? Ishmael says it was taken with a digital camera. The pixel spread and colouring ties in with the natural light on the stones and faces on the figures.
I think the reason it hasn't shown in the 2nd shot is that the person by the tripod has stood up. His head is in the approximate line of vision that the light was in and may be obstructing the reflection into the camera. The orb is quite large because the memory chip is trying to configure the image but maybe doesn't have enough pixels to translate it properly.
Just a thought?