Almost the same except the one case. As Google shows a cached thumbnail of an image while an original image is being fully loaded, if network is slow enough and if you right-click the image fast enough, you will get an address to thumbnail image, not the original one.
I'd add the direct link as a parent comment if I were you so people can vote it up, as this is what I found and used earlier after discovering the reason for the disappearance. For those wondering it does actually include a userscript version which is appreciated.
