Wait.. Do you want to know if it's a Small date or Large date as you title states?.. Or a Doubled Die? Which one is it?
Based on your pic I'm unable to tell other then the weight so here a pic for you it helped me when I started. Dave
Based on the picture, it looks to be a small date and not a doubled die. I can't really tell too much from your picture, but that's what it looks like to me. The letters look thinner and farther from the rim, which would suggest a small date.
The pic shows a small date and a weight, what we don't know is if the scale was erroneous or calibrated correctly. The coin looks like a copper-plated zinc, and the scale looks old and used where it may be giving false readings. The probability of this being a 2nd 1982-D Small Date Copper is very remote, thus my skepticism. Michael K may be right on the "creative photography" angle, too...Spark
Or it could be a photoshop montage. A 1982-D small date zinc in one half, and a scale showing 3.1 in the other half. The coin looks zinc to me.
Or maybe he put sand or something on the scale too (enough to make the scale to say 3.1g) outside of the frame.