It's a mechanical suit used for battling other mechas, but isn't that big compared to most of its adversaries. This was before their exodus to space, so the mechs weren't built with seamless morphing parts.
In this world, the "Spirelords" used soldiers in things like these to combat hordes of biomorphic constructs (that are the memories of past people and are looking for "heaven".)
The constructs are very attracted to energy expenditure, so they have to be taken out hand-to-hand.
= a random drawing that ended up being modeled in Sketchup and rendered in Max.