(at 46:55) When Magnum sees the three men on the boat that he was supposed to go fishing with, there is a woman in a blue bikini taking a photograph of them with their catches of the day. That woman is Jillie Mack, who was Tom Selleck's girlfriend at the time, and his wife less than two years later.
The picture on Rick's (Larry Manetti) shelf is that of Alice Cadogan, who portrayed Rick's sister Wendy in Season 4 "Distant Relative" (1983).