The QR Code Canarytoken allows you to place a QR code somewhere that an attacker will find it. Determined attackers mapping out a space will often follow any lead (including checking out where a QR code leads) which gives you an alert and tips their hand.
The optional redirect option
Much like the Fast and Slow redirect tokens, this feature allows newly made QR Code tokens to collect a fingerprint of the attacker's browser while redirecting them to a different landing page. This has an advantage over regular QR tokens - which send the user to a blank page - in that they are less likely to tip the attacker off to the fact that they've been fingerprinted.
You will also have the option to change the redirect type, matching the behaviour of the regular redirect tokens. These behave very similarly and both will redirect to a second page, but the slow redirect option will also collect browser and browser plugin details from the attacker. Your token will use the slow redirect behaviour by default, but this can be changed from the drop down menu just above the Create token button.