You need to show $12,000 in your account at the time for applying, you only dont need it when you are employed in Ontario. If you are employed the provinces other than Ontario then you will need to show $12,000 funds in your account.
I didn't go through ONIP I have I full time job and the company I work for gave a letter and said they would offer me ongoing employment for atleast the next 5 years, so I think that is what the difference is.