To make it easier to see what an application looks like before going to the trouble of downloading and installing it, we've made a number of improvements to the way we show screenshots on Download.
First, we took every screenshot we've ever received from a software publisher over the past 13 years (anyone remember Doom 95?) and reprocessed it for improved clarity. Then we created a larger preview version of each screenshot and moved it to the top of the product page.
Finally, we no longer send you to a new page when you want to view a screenshot at full size. Instead, clicking the preview image opens a light box where you can cycle through all the screenshots at once. It's particularly nice for games where there are typically a number of high-res preview images available.