It is my understanding that following the continuous ledge to the right of the red rock is the catwalk,and the red lines shown in this photo are the bypass, which merges with the main route just after the crux of the catwalk.
Since you said that you found out later that this wasn't the catwalk, I'm wondering what source you heard that from in case I'm also mistaken.
Frankly, that lower section stays closer to the ridge, so I'd consider it the 'main' route and the other variation as a bypass since the main route isn't contrived. Perhaps a name distinction between the two section is in order? . . .