Please watch the video and then tell us what would have been a good screenshot.
As far as a screenshot for product? Not sure, it really stays out of the way which I like but that makes it difficult to convey visually. Which you seem to have realized :)
I realize that watching a video is maybe how a lot of product companies wish potential customers made decisions, but much like an elevator pitch, if I can't scroll the website and have a glance at what the product looks like, I ain't gunna watch a vidya bud.