As per the flight monitor, the flights labelled A and B were supposed to leave first at 0815 HRS. But flight C finished all turnaround services and passenger boarding. Hence, it was allowed to taxi first, even though it was scheduled to leave after A and B.
P.S: Delays frequently on the two extreme-right stands and occasionally on the 3rd stand (from the right) as well. Even if flights occupying these stands are scheduled to take-off first, they tend to wait until other aircraft take-off.
This thread got closed, so I couldn’t post it there.