But I do think that you are missing a trick: you are pushing the wrong end of the proposition.
If this does fly it will fly not because you are offering a free appraisal of what users are wearing but more because you are giving users the opportunity to flex their fashionista status.
What you might want to do is create a panel of informed and preferably well known gurus to critique the uploaded selfies.
Go the X-factor for style route:
Your top tier of acknowledged experts critique the style 'performances'.
The 'judges' reactions to the style performances might be good or bad in the general but often enough your going to get a performance that has the potential to go viral: fb, buzzfeed, national press whatever.
Follow through on the personal aspect of these stories and create compelling narratives:
"OMG I totally took on board what (take in name of top stylis at Looks Good) told me about my style. I did what they told me and landed my dream date/job/ etc."
If you have any promotional cash to spend use it to recruit a panel of top stylists. Or if your bold enough take the roles on yourselves and spend the money on clothes/ haircuts.
In short feed awesome stories to the major players with big audiences and hope that a few stick. Obviously always point the origin of the story straight back to the app.
Good luck!
PS: Final Para: A simple yes or no from you could prevent them from making a mistake or give them encouragement they need.
Should read: A simple yes or no from you could prevent them from making a mistake or give them the encouragement they need.
Be outrageous and have fun.
If you need any help your copy reach out, I'm happy to help.
Let me think on the user acquisition issue, I'll ping you via your site.