You can still see the original paint, (or previous paint) under the current paint that has been exposed around the rivets and on the skin lap joints....
This is CORROSION, and while minor now, you will have to have it addressed at some point before it gets worse.
Corrosion in the middle of a panel is something easily dealt with by scrubbing it away and repainting the affected spot. Corrosion at a seam or rivet line could be something horrible that requires rebuilding a structure to eliminate.
Corrosion is like cancer. It grows and spreads over time. Once it's found a way to crawl into the airplane, it has become (near) fatal.
