At our property, we have two monitors showing the views from 32 cameras. The way the thumbnail pictures are set up, you can follow any action in real time in order. So things would appear in progression. We can follow someone from the parking lot through the door to the elevator to a room without any lapse in footage.
In the very early hours, our night auditor pretty much just stares at the monitors. After the paperwork is done, there isn't much else to do and pretty much any activity at that hour is still sporadic enough that it raises your interest. Before the breakfast host, MOD, housekeepers, front desk gets there, night audit is the only real line of defense for most hotels.
Audit shift is typically 11-7a, so it could either be audit or someone working the front desk that recognized her. My bet would be that someone on audit noticed her and stuck around a bit. Shift changes are busy times and I doubt many people would be paying attention between 6:55 and 7:15. It's when you run your reports, change signage, count the drawers, open the pool, etc, etc. This is pretty standard in most properties at which I've worked.
Maybe I'm being overanalytical, but I can tell your our auditor would totally have noticed this activity and he'd be the first one thinking it was hinky. Auditors are a special breed. Night owls with a lot of time on their hands and they're generally hypervigilant to odd activity not just for hotel security, but for their own. I'm sure the monitors and DVRs for the cameras are in the front office, as they are in most hotel properties. This wasn't something they likely had to research in some computer room. It was probably a case of the employee watching it happen and running it back when they looked at Shaniya's picture again. It operates just like a cable DVR for the most part, if the system is at all modern. In a newish hotel, it likely would be.