Profile Swap

I love your idea of swapping profile pictures with another person; it is quite unique and interesting. Because it is the picture of another person rather than some arbitrary avatar which is obviously not meant to be a physical likeness of yourself, it brings up some potential issues. Due to it being another person, this could be looked at impersonation, which is most likely violates the terms and conditions of your social network(I'm assuming Facebook, for which this is certainly true)

https://www.quora.com/Is-it-illegal-to-use-someone-elses-picture-a-photo-of-a-random-person-you-found-on-the-internet-as-your-Facebook-profile-picture

Though since you clearly have some understanding with the person's whose picture you're using, things should be more acceptable, especially for the purposes of this project.
Alternatively you could use photoshop to transplant your faces between the photos. This will serve to not only take you out of that gray area, but also due to comedic value, may
invite more comments and the like.

I find this concept very interesting because most people expect a profile picture to either be the person or represent him/her in some way, yet (I'm assuming) it won't. I am curious how many mutual friends you two share and then if people will get you two confused, i.e. sending you a message meant to be sent to her, because people usually identify others based on their picture (at least for chat heads). I'm looking forward to what kind of reactions you will receive, and whether they will take it seriously or treat it as a joke.

I think it's a great idea! My idea was also that I would put a friend's picture as my profile photo, so when I saw your idea, I was very curious about how the results are going to be; will we get the same results or not?