Thats why Mercator is not a good projection even for comparing countries this way. Because for reasonably-sized countries, north and south are still distorted.
For an extreme example, try to lookup Chile and put it over Portugal, a similarly shaped country. Watch how Chile is vastly different whether you put its southern or its northern tip over Portugal.
On one hand Chile looks like it might be less than 10 times the size of Portugal, on the other hand it looks like it might be more than 20 times Portugal.
Maybe this explains why New Zealand looks like it has about as much land area as California even though California is actually about 60% larger than New Zealand.
There's no way to take the surface of a sphere and flatten it out into a rectangle without distorting it in some way. It's called 'projecting' from 3D to 2D.
The projection used for the underlying map here is the Mercator, which stretches everything near the poles. It makes Greenland look almost as big as Africa, which it is not. It's the most common projection, but it's awful for accurately visualising the whole world at once.
But the Mercator is actually a really good projection for stuff like Google Maps, because it keeps shape and direction (not scale) accurate all over the world. Say you zoom into Iceland and then Ecuador... OK you'll need a different zoom level to get to the same real-world scale (e.g. to get to 10 miles per inch you need to zoom in closer to Ecuador than Iceland) but who cares. What matters is that, in either location, north is pretty much straight up, east is right, south is down and west is left. And also, a 10 mile road going east–west will look about the same length as a 10 mile road going north–south.
Other projections don't have these qualities, but are better for keeping overall scale the same all over the map, making relative sizes of countries look more like what you get on a 3-D globe. But most people just use Mercator for everything.
The rotation code is actually done, you'll notice China is rotated when you first log on (as is the US just a little).
Creating sane UI for you to rotate countries yourselves (that works on top of google maps) is going to take us a while. But it's on the todo list after better State/Province data
The author of this tool should use history.replaceState instead of history.pushState. Otherwise the way the page saves state using the HTML5 History API makes it impossible to use the back button.
Except, this is the Mercator projection, which distorts the size of objects as latitude increases from the Equator[1], rendering the whole website pretty much useless.
Consider using something like the Gall–Peters projection[2]. It is interesting to compare continents at their true size.
That's what I thought at first but if you search for a country then drag it around, it will change its size as you get closer to or further away from the equator so it takes the distortion into account. So maybe pointing out the distortion in the Mercator projection is part of the point?
Yeah, I took that as the whole point. You can overlay one country on another to see how they relate despite being at wildly varying latitudes on this projection. E.g pull Greenland down to India.
The country overlays change size as you move them north/south. Showing how the Mercator projection affects your perspective on country size is the whole point here.
The downvotes are likely because parent is giving the impression that they couldn't be bothered to spend 3 seconds finding out what's going on before commenting about it.
The point is that comparing shapes of different sizes still overly exaggerates the scale of the bigger one here. It does not allow for any kind of "true size" comparison.
More information: https://en.wikipedia.org/wiki/Map_projection