since post 1982 pennies are an 8 micron thick layer of copper plated onto a zinc core. This was done due to cost and because they make coinage for commerce, not collectors. But us whacko collectors still persist. That thin layer presents a whole host of problems with the plating rising due to some corrosion of the zinc core, or a variety of other situations. What you see is a plating blister. It happens to be next to the 2. It happens that you want to correlate it to looking like another 2. But it's not. But is the plating blister normal? YES. here's another misc blister ... referenced as a "spitting lincoln" https://www.cointalk.com/threads/1991-cent-spitting-lincoln.332971/ of course, he's really not spitting and there is no "spit die" to create this. Blisters and surface irregularities on these cents can get really, really bad.
How does this blister form a 2 under the other one, it's not just a straight line, look at the 2 itself
Blisters are not always straight It may look like a 2 because you want it to look like a 2. Why isn't it a Z? Or something else entirely?
The mint mark for these later years were not struck into the die by hand like earlier coins, it is engraved into the single die used. so it by itself can not be doubled at the mint by repunching ( RPM) like in the past. Read about "Single Squeeze" die preparation vs. multi-squeeze as in days long gone. Jim
