Pictures are the very important worth out the right tools for the job it takes an art to get a good picture. Have to think clarity, stability, lighting. If you hold the phone/camera close you will likely loose clarity unless you have a macro lens. If you hold it 6 to 8 inches away you will likely increase clarity and have to zoom causing the need for good stability or if you are slightly moving the exposure will be blurry. Lighting Egh once you get those 2 then worry about that haha good luck
I doubt it is missing cladding on that area. It is probably a stain or corrosion on that area. You might try keeping it in your pocket of change for a time to see if the coating comes off the high points on your coin. But as damage to a coin, there would be no premium for it. If it were missing cladding, then you would expect to see an incuse area on the coin.