Here are a couple ways to build the snapshot focus effect in Articulate Storyline. It's one of my favorite techniques for quickly creating interactive scenarios or "ask the expert" style interactions. The first example uses Storyline's slide layers.
The second example uses slide masters. The output is the same, but there are some subtle differences in how the learner interacts with the content.
I can think of a few more ways to approach this in Storyline. So if anyone's interested in adding to the demo pool on this one, go for it! We'd love to feature what you come up with.