JLPT N4 Grammar: ～てすみません (How to say "I'm sorry for doing..." in Japanese)

Natsumi Kotono introduces a lesson on apologizing for delays and other situations. She provides examples of how to apologize in both professional and social contexts, emphasizing the importance of timing and context. The video concludes with a summary and thanks to the audience.

What is the significance of the phrase 'It's okay to be casual' in the context of the text?

How does Natsumi feel about calling her friends late at night?