If I understand this right, we are looking at the this spawned character blueprint’s arm mesh, grabbing its animation component and projecting that data into a variable with the template of the actual animation blueprint that currently exists to run these arms which is itself a child of the animation component. This allows us to get (or actually “set”) the IsAiming bool that is being used there.
It gets extra complicated because there is a chance the data I’m casting won’t fit that template and the node will exit on “Cast Failed”. 
Can anyone else clarify a good way to think about this?