What's happening with this seedling?

Hey gardener! Your seed didn't grow upside down because plants are genetically programmed to let the roots go down and to have their stems come out of the soil, and even if planted the other way around, it will still manage to grow properly. What’s happening here is that you no longer have cotyledons, either because that part rotted or got cut off while growing, because what you see coming out is the part that should have the cotyledons and the seed attached around it. At worst, try to take it out of the soil to see what's happening underground. Good luck, bella ciao!