Facial recognition in the workplace

What exactly are they using the FRT for? In a place-of-work context, where the subjects in the video are employees, identifying them generally isn't a problem.

It's a very complicated and nuanced area of law, so it's not really possible to say that it is "legal" or "illegal" full stop; it will depend on exactly what data the employer is collecting, how they are processing it, and the purpose for which they are collecting and processing that data. Using FRT in the context of security controls (for example, to unlock workplace devices or allow authorised employees access to secure areas) might be deemed a legitimate use, provided the data collected is only used for that purpose. Combining FRT with CCTV to arbitrarily track the movements of all employees throughout the day would almost certainly not be considered a legitimate, reasonable, and proportionate use of that data, barring some sort of extraordinary circumstances (and even using CCTV alone for that purpose is not generally permissible, even without the use of biometric data).

I know guys that work in (particularly) hotels that are sometimes docked hours/days cuz the Employer says no one seen them between such and such hours and that maybe they had left work when clocked in. Maintenance guys. Useful for the employees there. Id imagine it's for circumstances like this.

Consent is one possible legal basis, but there are other possible legal basis.

The problem with relying on consent is that it can be withdrawn at any time, which would leave any employer in a difficult situation. Employment can't be conditional on consent to data processing. It's not true to say that 'biometric data cannot be processed without explicit consent'.