Google has moved the AMP icon from the bottom left position to the top right position of the Top Stories carousel cards. I am not sure exactly when it was moved, but for as long as I can remember, that AMP icon was on the bottom and now it is on the top right position.
Here is a screen shot of the AMP icon at the top right:
Here is what it looked like when it launched, it soon later went from green to gray but the position of the AMP icon remained at the bottom:
This was spotted first I believe by Mordy Oberstein on Twitter. This is a tiny change but Google did it for a reason.
Forum discussion at Twitter.