With the new Swiss Pass it seems one does not have to show it to the ticket controller if one has bought a ticket online or with mobile? When he scans the code the picture of the person comes up on his screen.
Sounds like you have to show your face!
What wizardry is this?
I'm not sure if the picture comes up, or if there is a message or something. Also for this to work you have to link your swiss pass with the SBB app. A ticket controller showed me how to do it once on the train. You still have to have the swiss pass with you, you just don't (normally) need to show it.
It's a good system.
If you purchase a ticket using the SBB smart phone app, you get a large QR code that you show to the ticket inspector.
Scanning the QR code brings up a photo of you and confirms if you have a valid SwissPass, etc.
In these cases, there is no need to carry your half tax card with you.
In the app you can also add other travellers (e.g. family) so you can buy tickets for them, and if they use the same app password on their smart phone, they can show the QR codes of the tickets bought for them.
For me the main downside of the SBB app is you can't pay with Reka.
The downside of the Swisspass is you have to renew it annually (no more three year discounts), and you can't pay online with Reka.