I had two very casual interviews, via a recruitment agency.
The first interview was very informal - the questions were very basic and I felt that they were just trying to get information off of me (asking me to repeat some of things so they would have time to write them down).
They seemed happy with how the interview went, gave good feedback to the recruiter (I seemed like a good fit for the company) and asked me to come in for a second round, where I would do a presentation.
I did my presentation, and they didn't have any questions, feedback or comments. I found it a bit awkward, as usually there are some questions/comments, but left with the feeling it had gone well.
Some days later the recruiter told me I didn't get the job but they weren't able to provide any constructive feedback, only that they wouldn't be proceeding with my application.