Eric, with that type of connection of the flat roof, there will be a difference it height between the fascia lines at the corners of the tie-in, and is considered structurally attached. In the original picture, the fascia lines are the same height. This can only mean that the flat roof rafters are attached to the face of the exterior wall (not on top of the wall), or attached to the sloped roof fascia.
The only reason it looks this way is because it was installed wrong. The roof is actually is pitched backwards into the main roof.
I know what you are saying about extending upward, but, when they meet in a corner or are on the end of the main roof, either side, the fascia height is the same and they are connected to the main roof trusses as well as resting on the support wall. Just like in the OP 1st post, 3rd pic.
Eric, you just proved my point on the second pic. Look at the inside corner next to the elec mast. The fascia is not at the same height and indicates being structurally attached with the flat roof rafters over the top of the wall. Remember to look at the TOP of the fascia.
On that roof, yes. On the OP roof, the fascia is the same size. They are both connected to the structure.