At both my gyms (USAIGC Copper 2, and later Xcel Gold) we did a variation of this. Not at every event but at the beginning of practice we would line up because we would get a quick briefing on what to focus on as well as get split into groups. We were expected to stand in height order and with pretty feet/legs/arms but not salutes. At the end of practice, same thing, we would line up in height order, stand pretty, listen to head coach's super short speech. The practice before a meet would usually come with directions, sometimes we would acknowledge a new skill/rip, and if it was someone's birthday, that was when we sang. We then salute but not thank and clap out. The number of claps usually signals something like the age someone turned for their birthday, number of people at practice, etc.