help: second interview

got a phone call from HR arranging the second interview.

Since it's my first time to do second-interview, could someone please tell me what I should focus on?

I'll be meeting with the same manager who interviewed me at the first time. She already introduced the company and the team and I've already talked with 2 of the team members (tech guys) at that time. the interview is set at 11am, close to lunch time, am i supposed to have lunch with them ? The HR girl knew nothing about the details except the time, she just said "not sure about the details"...

Any suggestions ?

Thanks in advance!