Wow! Lots of different takes on this idea...mostly over the control issue...
That's interesting to me. I'd love for someone to take control on occasion. Whether it's, as you posit in the opener, total control or whether it's just by way of volunteering helpful hints ("Now deja...that belt doesn't go with that long skirt, try this one!)
In any event, as a few have mentioned, it's a form of validation from the SO or friend that they actually enjoy and approve of what you're doing. And therein would lie the thrill! An unequivocal and equal sharing!
Yes, please! I'm all yours!
And later...you're all mine!
:D