"The Allure is a rather complicated mechanism the Veela have. Imagine it like a siren’s song, but entirely magical. It reaches into the soul of the person and pulls them in. It’s meant as both a defense mechanism and a way to find their soulmate. When a Veela has full control over it, they are able to keep it in check. As for the attraction part, it mainly depends on the person’s deepest desire. If.. let’s say they have someone they truly love and care about, not even the beauty of Veela can pull them away from that person." Basically, anyone who wasn’t attracted to women wouldn’t be affected by the Allure. This gets murky when you start to apply those like Fylaneiros. It also didn’t work on those who were strong willed. Another reason why Daphne wasn’t affected, but I prefer the other reason.