Sometimes it happens that a slide needs many screenshots to display. Squeezing 1024*768 shots into one screen makes them barely readable. A solution is to magnify some parts. For so I've created a rectangular callout with a copy of the selection. But still can't get it how to make it appear larger after the contraction.
Would be nice to make the progress bar appear inside the bigger rectangular to make it noticeable.
How are you creating the screenshots? Wndows screens capture or a 3rd party screen capture tool.
I use Techsmith's SnagIt which has a feature called Spotlight and Magnify which makes this as a simple as a few mouseclicks.
There are other tools on the market offering similar features.