British Rail Stock Shots - King's Cross Station Stock Shots

The transcript contains a brief confirmation statement, 'Yes it is.'

What does the phrase 'Yes it is' imply in a conversation?

In what contexts might someone respond with 'Yes it is'?

How can the phrase 'Yes it is' be interpreted differently based on tone?

What are some alternative phrases that convey agreement similar to 'Yes it is'?

Can 'Yes it is' be used in a formal context? Why or why not?