Favorite Images are determined by the number of members that have added an image to their favorites during the last week. Should a tie exist between two images (as it often does), the winner is determined by which image is the newest image. If an image uploaded yesterday has the same number of favorites as an image uploaded last week, it most likely is the more successful of the two images. Members can only add an image to their favorites once, and careful checks are performed regularly to ensure no one person has duplicate accounts to house favorite images.

The key here is how many times the image has been added to someones favorite list in the previous 7 days.  So although this person may have had less "adds" than your image, if they were all done within the 7 day timeframe and yours was spread out over a few weeks then that would be the reasoning behind why their image made it and yours did not.  The system doesn't take into account what "gallery" the image is in, its not revelant at all whether its a fractal, a vue image, a poser image, etc. Its all based on the adds to favorites..

Hope this helps explain.

Thanks