A similar question has been asked previously, however the answer is not relevant to my problem.

I have a number of photos where the thumbnail in the gallery does not match the photo displayed by the viewer (HTC Desire, stock gallery and photo viewer).

for instance, take a picture of a child on a swing.

The thumbnail appears to be an image taken a fraction of a second earlier than the photo the viewer presents. The child is framed to the right of the photo in the thumbnail but to the left in the full view. 

Is anyone able to explain why this is the case?

Also, am I able to rescue the image presented as the thumbnail (which is a better framed image)?