I think there have been real-world studies that show people trust and feel more comfortable around people who are similar to them - hence he's showing people the most ideal and trusting person they can imagine, which is themselves. Combine that with the chemicals he apparently gives off, and its likely he's exhibiting an aura that is most appealing to his subject. And I would suspect that all this influence - even the visual - is on a subconscious level, so the person he's trying to influence isn't outright thinking "wow, that person looks just like me. I think I should trust him/her."
So his power isn't intended to "seduce" in most cases, but rather make folks more comfortable around him, and to portray himself as most trustworthy as possible. It's all about his Aura - which really is a fitting codename for him, now that I think about it.
I liked the story and agree it was a nice change of pace. I enjoy a good epic cross-over and on-going story as much as the next comic fan, but sometimes you just want a stand-alone issue that works on character development, and that's what we got here.