These early pinups were often marketed as "French postcards," and they were popular among soldiers and sailors who were looking for a bit of fantasy and escapism during their time away from home. The pinup style really took off in the 1940s, during World War II.
As an image to be literally pinned up (on a wall or locker door etc.), the pin-up was born in the United States in the years 1920 1930, during the golden age of the press.
The game is called spider solitaire due to the relationship between spiders having eights legs, and the eight foundation piles that need to be completed in order to win the game. While the current version originates from 1949, the first mention of Spider comes Games Digest published in 1937.
Ghost is a lieutenant. The Call of Duty wiki didn't specify his age, but typically someone could join the military aged 17-18 (UK's minimum is 16), so let's assume he joined during his teenage days. Being a lieutenant, that means he's probably in his mid-to-late 20s, almost 30.
Modern Warfare 2: Ghost is a six-part comic book mini-series. The series ties-in with the 2009 video game Call of Duty: Modern Warfare 2, focusing on the character Simon "Ghost" Riley.