Once she was out of the bottle, Jeannie spoke Persian - not Arabic, as is often stated, because the producer Sidney Sheldon was unable to find a tutor for Barbara Eden to learn Arabic phonetically, and had to settle for a UCLA professor who coached her in Persian. Jeannie began speaking English after Tony wishes her to.
Although it looks like a beautiful sunny day, it was actually a cold December day on Zuma beach, Southern California, where the desert island scenes were filmed. Indeed, Barbara Eden has been quoted as saying that it was a good thing it was filmed in black and white as her lips were blue.
When this pilot was originally filmed, it ended with Jeannie in Tony's room and him ordering her to leave. When the show was bought, the censors said they had to add footage of Jeannie's smoke leaving Tony's room so that no suggestion was made that she stayed the night in his room with him! That began the list of rules that had to be followed including that any scene showing them in the bedroom together must include one or both of them leaving the room.
Jeannie (in bottle) snuck her way into Tony's gear as he was leaving the island. The bottle was uncorked and the original stopper was left behind. Back in Cocoa Beach, Tony improvised with a clear glass triangular glass stopper from a 1956 Old grand-dad whiskey bottle, which appeared throughout Season 1. The original stopper was recovered in the first episode of season 2 when Jeannie and Tony revisit the island.
While Tony is laying out an SOS sign in driftwood on the beach, the soundtrack is playing SOS in Morse code.