Testing and sharing.
In order to quickly get ideas in front of stakeholders and the developers, I created a number of mockups in After Effects. While it's useful to look around at other websites and apps for inspiration, the need here was very particular, if not unique. So it was a great help to be able to give everyone a clear demonstration of each idea with a rough animation.
The first thought was to have video stills emerge over the text long enough to be enticing but not so long as to be in the way. But the user had no control over when the video prompts appeared.
Another option was to indicate what is available to the user as soon as the page loads. But this felt more like an interruption than an affordance.
Another plan was to have a little bit of video play as the user touches the clickable area. But stakeholders felt this was too subtle.