Image uploads (i.e. ads) take a few seconds to analyze. It could be 5 or take 10-20 seconds, depending on traffic and you connection. In any case: it's fast.

For webpages (above the fold), this is the same. Full webpage heatmaps take slightly longer, as you will be getting multiple heatmaps (the number depends on the length of the page). When selecting the Scrolling Heatmap option, you will get an additional video-heatmap (see below).

Videos have a longer processing time. In essence, a video is comprised of hundreds of heatmaps. For instance, when uploading a 30 second 60 FPS TV Commercial, you'll be generating 30x60= 1.800 heatmaps, so this will take a few minutes. Don't wait for it: you will receive an automated (email) message when it is ready.