If a participant identity was shown correctly they touch the "I agree" statement and it turned red to acknowledge the touch.

This resource can be downloaded or viewed using the link: acon3_idcheck_ok.png

If you have wget available (typically on linux systems), then you can also obtain a copy using the command

 wget  -nd  biobank.ctsu.ox.ac.uk/ukb/ukb/images/acon3_idcheck_ok.png