ok, so here's how it works (or how I think it works based on my experiences and a few others on SDN)
1. You submit your app.
2. They do stuff behind the scenes on their side to verify it
3. They have this "online database" from which schools can dowload your app directly. I.E. if "Sarah" has applied to X, Y and Z schools, then each of those schools are always checking to see which students have applied on this secret AMCAS database....they check for people like sarah that have applied to their school, download the application, and get the ball rolling from the School's side.
4. Then you get secondaries, YET, you have not been verified.
5. Once AMCAS officially verifies you, they send in the verified app to the school and that's the one schools use to screen you or not.
Note: The Welcome Page will say that X Y or Z schools have been transmitted, but that is **NOT** always the most accurate date. There is a difference between when schools dowload your application from the database, and when they dowload your app once it's been verified. Thus, if you click on the Print button and see not dates, this means your VERIFIED application has not yet been seen by the schools. Get it?