I don’t live in any media culture world. I sincerely don’t know what you are talking about.
Most of the mass attacks in this white-majority country are carried out by white people. Which means the odds are that THIS attack was done by a white person or persons.
So what?
The video seems to show both men walking towards the finish line - i.e. away from bomb site two and towards bomb site 1, both with backpacks on. Then the stills show white hat back at site 2 calling (maybe calling the bomb at site 1).
Does not seem to be a logical way to do this, unless they walked to site 1, drop the bag, turned around and at least white hat then walked to site two, called the first bomb, dropped the second bag, and the left and called the second bag.
What part of the sequence do I have wrong?