The pilot shows Don walking upstairs to see the kids in their bedroom. In the rest of the episodes in the Ossing house, Don and Betty's bedroom is on the second floor. The exterior shot of the house shows it to be a two-story house with a third story with dormer windows. The exterior shots of the later house is different -- although both are white with red front doors -- two story with no dormers.
In the opening, Don asks Sam the waiter to light his cigarette. Don raises his left hand and cups it around Sam's lighter. The camera reverses angle and now Don's left hand is on the table top.
In Pete Campbell's first scene, the picture Pete Campbell holds while referring to his then-fiancee Trudy is not a picture of Trudy (Alison Brie).
A secretary is shown using an IBM Selectric II typewriter, which was introduced in 1971. The show is set in 1960. (The DVD commentary notes they were aware of the anachronism. However, period-correct typewriters were not practical to use when filming)
Wall calendar in doctor's office reads March, 1960 when Peggy goes for a prescription for "contraceptive pills." The first birth control pill was approved by the FDA in May, 1960.
Lucky Strike's "It's toasted" slogan came to use in 1917.
In March, 1960 Don Draper says "It's not like there's a magic machine that makes identical copies of things." The Xerox copier was introduced in 1959.