The more common concept of margin used in this context is net profit after expenses, including labor expenses. The question is therefore roughly "How much is purely for capital profit taking rather than directly involved with compensating labor and purchasing materials?".

Everything is human labor. There is no such thing as a “resource” without human labor to convert raw earth into something useful.

Help me understand this.

There's the cost that the employees pocket, and then there's the share that the shareholders pocket, right? Doesn't "margin" represent the latter?