While in PIP Designer (Add/Edit Motion for the PIP effect), I want to add keyframes so I can control the effect from keyframe-to-keyframe but the "add keyframe to current location" button is grayed out. So how do I add keyframes?

Second, while still in "PIP Designer (Add/Edit Motion for the PIP effect)," there is a little box inside of a bigger box on the image. I haven't been able to find a description on the relationship between the two boxes, each of which can be resized. What is the relationship between the two and how do I use them to create movement and effects.

I also notice a box that contains my PIP in the regular review window that has a blue cross in it. But when I try to resize in the review window or move the PIP box, nothing happens. What's the purpose of the box and the blue cross?