There are videos of this missile system available on youtube. See my posts from a couple days ago.
Whidbey Missile Launch anons - see this video at 2:32. It should clear up questions about the long exposure frame and the missile exhaust. Keep in mind this is a gimbaled thrust system where the nozzle of the missile will adjust and change direction to optimize thrust.
https://www.youtube.com/watch?v=JcB4eJ6lHOY>>2372682