First, here is a TUTORIAL on basic Keyframing. It was written for an earlier version of Premiere, not Elements, but covers the basic theory.
Now, in your example, think of the Video Frame as a picture frame. It is fixed on the wall, and you have a picture inside of it, but can see nothing outside of that frame, only what is inside of it. What you are doing with Effect>Motion>Position is moving the picture behind that Frame. Same with Motion>Scale. Now, with keyframing, you can alter the position of your picture behind the frame over time.
Hope that this helps.
PS - welcome to the forum.
Thanks for a lead.
You are most welcome. Keyframing is a bit of an abstract concept initially, but once one gets their head around the idea, a most powerful and useful tool is unlocked. Personally, I do not think that there can be too many Keyframing tutorials, as they are so powerful. I doubt that I do more than a few Projects where something is not Keyframed at some point. I rely of Keyframing of Effects to do things in PrE, or PrPro, that used to have to be done in programs like AfterEffects.
Good luck, and trust me, every minute that you spend learning Keyframing will be directly rewarded later on. The more you learn about it, the more uses you'll find for it.