You know, when I read this, I thought the blessing was something like a "relaxation field" plus making MC look cute. Not mind control.
The way the elf girl reacts is almost exactly like the way a male MC would react if he was resisting a cute pout from a little girl. "Don't look at me with those eyes!"
So I interpreted her blessing just makes her look cute to the person it is directed towards.
Plus there was the line where the elf told her that the blessing will make her very comfortable (though that might be a reference to their wedding night) but even taken literally, I can only see it as the blessing being a relaxation aura.