No, it's not possible to sell a screenshot of an e-ticket that was originally issued as a pdf or Apple Wallet ticket. Our system doesn't recognize these tickets as original, and therefore, they will be blocked.
However, you can always just sell the full pdf or Apple Wallet file! You can always select which ticket in a file you want to sell, and which one you would want to keep. For Apple Wallet tickets, you can find a detailed explanation of how to sell these here.