It can be done but it has to be done in a round-about way.
When the larger image is shown use prt sc key on your keyboard to take a screenshot. Open up Paint, paste the screenshot into Paint.
If you want only the larger image without all the other stuff on the page and you have a version of Windows with the snipping tool you can then use the snipping tool to isolate the larger image after you paste it into Paint. Then save the snip. If you keep the larger page view in Paint, you will have to save it. If you snip the image from Paint, you don't have to save the Paint image if you don't want to.
Paint image, which has the advantage of the URL in it and could come in handy in the future.
edit to add: when you take a screenshot you will not see anything happen.
Edited by Queen-Evie, 07 May 2014 - 10:17 PM.