That is from a slight amount of grease into the deepest part of that design. When the devices get wider, they prevent the tops of the devices to be struck, making them shorter and wider:

That is what you are seeing. It will not be a
DDR in that location of the design. The
DDR will be in the centers of the design.

So like on this design of the image above, the target area has nothing there, so there probably not be a
DDR on that design. In order to have a
DDR, there would need to be design on that area to transfer.

This design would have a better chance for a
DDR. There is more going on, on the center of the design.

Nickels we know have the
DDO /
DDR's in certain locations, where the X hits the spot. Just an observation I've noticed. This will save more time in the searching, as to where to look for doubled dies on the single squeeze dies. Look smarter in the search, not harder. Harder will land you
Machine Doubling and die wear. Seek the target areas. (Also look at listed dies to see what to look for on these. That answer might surprise you) Smarter, nor harder. Nothing there? Move on to the next coin.