According to Fox News, the flight attendant came down before the plane took off and the flight from Nashville to Philadelphia went normally.
Passenger Veronica Lloyd clicked the video of this unusual moment on Twitter. It showed a flight attendant beginning to roll around inside the open overhead bin, seemingly greeting passengers and giving directions.
"Is this a dream @SouthwestAir ?," Lloyd wrote. "I can't get over how weird I find this. @SouthwestAir please get it together."
Lloyd said she was "perplexed" by the woman's actions and she was in the overhead bin "for a solid 10 minutes".
The attendant was seen resting on her side and stomach, with her feet hanging out of the compartment. While passengers were boarding, the airline employee rolled over on her stomach and started talking.
Southwest Airlines said in a statement that attendant was trying to have a "brief moment of fun".
"Southwest Employees are known for demonstrating their sense of humour and unique personalities.
In this instance, one of our flight attendants attempted to have a brief moment of fun with customers during boarding. Of course, this is not our normal procedure, and Southwest Crews always maintain safety as their top priority," said the airlines.
( With inputs from IANS )