So they questions are what are they doing? and can they, or at least the horizontal beam be removed? I predict ‘no’ but I’m curious.
They don’t even appear to be supporting the purlin. You cant see a gap in the pic but there is one.
The diagonal beams end like this and are held in place with two nails. Yep thats right, just two! The piece of wood on the floor is about 18" long and is only held to a joist with two nails.