It shows how the domestic railway could establish a facial recognition ID based ticket system, that could prevent fare evasion and crime, either with barriers that automatically open for ticketed passengers (at staffed stations) or flagging (at unstaffed stations), where onboard staff can then focus resources. Secondly in much of Europe ID is required to buy train tickets.
Maybe for repeat offenders or known criminals walking through London terminals. Hard to see how this can realistically be linked to train tickets, though - personally I would be very concerned about being asked to upload facial images to buy tickets. Equally I don’t think the UK will ever accept mandatory ID for political/cultural reasons.