OK so I am making progress --
it appears that the reason the SECOND TO LAST is displaying, is because apparently all images are displaying in a duplicate box; only, they disappear as their number comes up. Opacity is being given 1 to all but the last image, and the last image is given opacity -0.001, which makes it hidden, hence why you see the second-to-last instead of the last.
But what SHOULD happen is ALL but the first one should be given opacity -0.001 until their number comes up. (when their number comes up, for some reason their duplicate disappears, and the javascript manually overrides the page CSS for the HTML element with the opacity.)

