Oleksandr Petrakov overseeing Ukraine training session

What do you think the speaker is trying to convey with the phrase 'Hey you'?

In what contexts might someone use the phrase 'Hey you'?

How does the tone of the phrase 'Hey you' change based on the speaker's emotion?

What are some possible reactions someone might have upon hearing 'Hey you'?

Can 'Hey you' be considered informal? Why or why not?