Shrunken 1936 Wheat Penny

I can’t believe someone didn’t spot this 1936 penny before I got back in change at the store.I immediately noticed it was different in size and possibly copper content.In the 1st photo I matched it up with a new penny and the 4th photo with a 1957 wheat penny and it’s quite a bit smaller than both.I couldn’t find much on smaller wheat pennies from any year online..I looked at it with a loupe and there also seems to be something faintly stamped in the background.It doesn’t look like anybody has tried to alter it.To me collecting coins is like watching the grass grow so I’ll give it to my granddaughter.