On more than one occasion I have fallen for this. So, why put a lure and sharp hook in a tree?
I see this ‘thing’ swaying, dangling, flying, whatever, over the bank of a stream or river. Next I quickly focus, shoot, and stealthily walk forward. The same result each time.

At first I thought this was a cast gone astray. However, I have found at least a half dozen in the last month or so. Are there that many poor casting fishermen?
I think there may be a subtle message I’m missing. Maybe the answer is in the rock art I find now too.