Lol. It's a matter of weight to lift ratio

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But really, that's a good call. This isn't an rpg, where monsters just drop items and bags of money. A tiny synthase carrying a gold coin does seem impractical.
That said, I think it more likely to have been the same thing that had esmi as whatever it was at the end of WP. Whether that is an actual inchoroi form or a different synthase, I think it was the same thing. Glamor to cover the form.
While yoirs seems like a pretty good explination locke, the one piece that doesn't quite fit is esmi's physical response to the man\glamor\thing. Her "skin felt like water" at his touch really matches the skin spy response later on when the wing tip touches him. To me, this demands that the synthase was there, touching her.
In her state, if it really was just a man under compulsion, and if she didn't notice a bird filtering around cumming on her , it's entirely plausible it came in and did some feather touching...
For my money, I'll stick with physical manifestation under glamor. It just seems cooler.