That would be a privacy invasion, as users, by polling, could figure out who is on each stall, and, from there, how long everybody spends there. It also allows everybody to recreate the detailed log that this system logs.

I would be careful deploying even the original indicator because of concerns that it might break some employment/privacy law. It is hard to prevent systems from leaking personally identifiable information, especially in cases where data is grouped over a relatively small number of persons, as appears to be the case here.