As we've mentioned, the FAA considers any flight for which you will be directly compensated, or in which you capture media that you will be compensated, to be a commercial operation. Even if you are flying a DJI Mini 2, which does not need to be registered with the FAA before you fly, if you will make money from the photos or video, that flight was, retroactively, a commercial flight, requiring you to have your Part 107 certification. We chat off the record with an FAA representative about this scenario, where you fly a completely legal hobby flight, but then decide later that you'd like to sell the photos. The FAA rep made it very clear that his advice is for folks to always fly under the Part 107 guidance. You can't sell 'hobby' photos from your drone, but you can easily enjoy a casual flight under the Part 107 regulations, then you have the freedom to do what you want with the media you capture.