Tell your friend to post a video with the sign. And post the picture from different angles and different sources.
Anyone can photoshop a Bitcoin QR code.
Thanks, that's a good point. I'll have him do that.
I tried reddit, but I don't have a very good account and it seems like it was sort of shadow blocked on that.
Publishing to Imgur actually got some views:
http://imgur.com/a/36NV7