Those are hurricane clips or straps. I'd imagine that there are more than these two, and that they're spaced evenly around the walls.
That wooden rail at the top of the brick work is called a "top plate" (in the US, at least), and is attached to the top of the brick with appropriate anchors. The roof rafters and ceiling joists are then attached to the top plate. Oddly, it does not appear that there are hurricane clips attaching the rafters to the top plate.
A high wind could get under the outside overhang and lift the roof off of the building, these straps are designed to hold the roof structure down to the building and prevent it from tearing off.A high wind could get under the outside overhang and lift the roof off of the building, these straps are designed to hold the roof structure down to the building and prevent it from tearing off.
If you live in a high wind area (where tornadoes or hurricanes are likely), then these can prevent significant damage. You may want to take a good look, though, at how the rest of the roof has been attached to the top plate, as it doesn't appear to me to be properly attached.
If you're not in a high wind area, it could be that they simply used these to attach the top plate to the brick wall instead of anchoring it down into the brick. This strikes me as a bit of a lazy way out that actually ends up taking more work. Instead of drilling and anchoring the top plate with fasteners vertically though the top plate into the top of the brick, it was attached with (likely many more) fasteners horizontally through the strap and into the wall.
