It made his great nose protrude more arrogantly; it emphasized his cheekbones; it made his eyes seem larger. There were deep hollows at his temples. His body was cadaverous. He wore the same suit that I had seen him in five years before; it was torn and stained, threadbare, and it hung upon him loosely, as though it had been made for someone else. I noticed his hands, dirty, with long nails; they were merely bone and sinew, large and strong; but I had forgotten that they were so shapely. He gave me an extraordinary impression as he sat there, his attention riveted on his game -- an impression of great strength; and I could not understand why it was that his emaciation somehow made it more striking.

Presently, after moving, he leaned back and gazed with a curious abstraction at his antagonist. This was a fat, bearded Frenchman. The Frenchman considered the position, then broke suddenly into jovial expletives, and with an impatient gesture, gathering up the pieces, flung them into their box. He cursed Strickland freely, then, calling for the waiter, paid for the drinks, and left. Stroeve drew his chair closer to the table.

请教老师：and I could not understand why it was that his emaciation somehow made it more striking. 中的 it was that 怎么分析成分和含义？ 感觉去掉it was that, 变成 why his emaciation somehow made it more striking. 含义也通顺呀？ 

还有一点，calling for the waiter 中的for应该去掉呀？因为call for sb 是去接某人的意思呀？