Curly Sue wrote:
I am watching some workers put a brick veneer on a two-story building.
The underneath (sheathing?) is what looks like plywood. Then there is
black paper stapled to it. Then the wall is going up, a single layer
of brick against the paper.

My question is- is a single layer of brick on the outside of a
building going to stay up? Do they lean it into the building?

I know there are multi-story brick buildings, but I guess I've never
seen one being constructed so I never thought about it. For some
reason I thought there would be some sort of bonding to the underlying
material.

Just curious :

Sue(tm)
Lead me not into temptation... I can find it myself!

What you're not seeing (probably) is the brick ties they 'should' be
installing in the courses. They're nailed to the wall and are mortared
into the mortar joints.