If a job interviewer talks more about himself and the company than asking you questions. Why does it means?

It means the company has hired someone who is incompetent and shouldn't be interviewing prospective employees. I'd drop a line to the President of the company asking if they are aware of the interviewer's technique - or lack of technique.

That means you're being informed about the company and YOU should be asking pertinent questions such as what are the duties, what's the most important part of the job, is there additional training available if needed, what's the sick day policy, etc.

Often it's someone who is inexperienced in giving interviews and/or weren't prepared. They talking about what they know and trying to get you to respond to get a feel for you since they don't have better questions to ask.

It can also mean they were told you were one of the finalist and they were checking more on how you interacted with them; not skill specific things.