Mine's bigger than yours...
 

The closest ones are...

didn't realize how big australia is

Yes, it's a genuine continent, not an island faking it.
The way they make maps screws up perspective.

It's nice of them to put them all near the East Coast so I can visualize better.

I think they keyed off DC for the most part.

Is there Canada and Mexico to post?

Nope, they didn't do those two. I suppose since the abutt on the map they are easy enough to compare.

Canada is larger in land mass, I believe ... all those uninhabited islands. Funny, the maps they showed us in elementary school always made the U.S. look very small compared to Canada.

Canada = 3.855 million mi²
....USA = 3.797 million mi²

The last three...

I think it would be helpful if the overlays were in this variable scale form AND all at one scale.
My eye loses perspective in this form from time to time.

How many different shapes can Canada be?

How many map projections besides Mercator do you have?

that depends on what feel you have for the US, and the distances between major points. Having traveled it helps a lot in getting a handle on how far is here to there.