I noticed that the SJ we see isn't an actual walking around suit. The ribs and parts of the arms are just retention/protection devices that clasp ontop of whatever is in the chair. IT kind of reminds me of the technology in the original stargate movie, where it just unravels from around the person entirely.
I have a feeling there is a human sitting in that chair and the "suit" conformed around him or her. The chair is obviously for a bigger creature/person than whoever is in it.
In fact, whoever is in this chair has pretty scrawny looking arms because there more room in the "Suit" hole than the arm takes up, and it reminds me of a kid putting on an adult's suit or something. Sure, it fits, but its wayyy too big for whoever it was made for.
Also, the neck seems a little small as well..