I guess the functionality would be okay as long as there was still a normal alternative of opening the full size image in a new tab - for example if you middle click on the image, or right click and open in a new tab. With the current javascript implementation, this is not possible - right or middle click do the same as left click, and the right click menu is suppressed.
A partial solution is to browse the site without javascript enabled, but this breaks other functionality of the site so isn't really too much of an option.
I hope you can appreciate these usability concerns.
Thank you!











