Would 20 images not be a bit a too small number? This could be probably found by testing against a larger sample. Have you tried this?

I didn't know about the Yolo algorithm and I have tried to look for an association of YOLO and jet images in the context of hadronic collisions (jet images are a thing in particle physics). Whereas I have found some hits, I was unable to find actual works that use it (only "rival" methods seem to be considered). I have no idea why (either there is a reason or this has never been tried).