Is it safe to show the QR code to his friends? I was opening my Jaxx wallet this morning and some of my friend made a pun saying they would take a phoyo of tmy QR code to buy some tickets with it. I was therefore wondering if it was safe to show the QR code ? What does it stands for ? Here is an example from the ETH forum.
It is your wallet QR code, so no, there are no problems that they have seen it..

Only thing they can do with this QR code is they can scan it and send you money :) 

This QR code works like copy/paste on computer, so that user don't have to type in that long wallet address characters he can scan your QR code and the scan will return your wallet address code :)