The painting seen above Bert Cooper's (Robert Morse) couch while he watches the moon landing is one of the "drip paintings" by the american abstract expressionist Jackson Pollock.
This episode takes place in July 1969.
The set and costumes of "Mad Men", set in the 1960's, reminded Robert Morse so much of the setting of "How to Succeed in Business Without Really Trying" (in which he won the Tony Award) that he initially went around the set singing the song from that show, "A Secretary is Not a Toy". The rest of the cast was so young that none of them got the joke. In this episode he finally got the chance to sing on camera.
Mid-season finale.