a Tumblr question

When a Tumblr post contains more than one picture, with certain numbers some of the images tend to be resized rather small with maybe only one image largish. And then when I click the images I just get an annoying slideshow that barely makes the images larger and actually makes large images *smaller*. Is there a way to click somewhere (or change a setting somewhere) that enables me to see the images at their proper size as they were uploaded? Or at least at the 500px width resize Tumblr does for single picture posts?

fanart, Best Laid Plans illustration Version II

Thanks to the awesome yue_ix who gave me not just a Facebook screencap, but a file made from it with the elements already sorted in layers and prepared for the names, I was now able to make my recent Pinky & the Brain story illustration appear on a fake Facebook site like it was in the story.

( image behind the cut )