No. The bomb was behind the barricade. Note how the barricade is wrapped around the mailbox. The blast wave came from behind.
I think you are correct. The two bags by the metal box do not even look like they were moved, let alone exploded. The metal box has not even been dented. This was mainly to hurt the poor people in the crowd.
Good observation. I’m a structural engineer and it’s staggering to consider the force it took to bend that barrier with pressure.
that’s what I thought, when I saw how the rail was bent