Here's a neat little video! We learn how to make a Picture in Picture effect in Resolve ! (Hint: it's pretty dang easy!)
The concept goes a little something like this:
Add the reaction video, or on cam video, on top of your main footage. Then use the scaling feature, plus the position, to place it in a corner that fits your video. Then to make it extra super snazzy, add a little border of color to make it pop!