Aaron Shepherd, a friend of the alleged victim, shared the footage on Twitter.
It shows a woman walking down the road with a man before stopping, stepping into a front garden, picking up a window pot and walking off.
A Met Police spokeswoman confirmed that the force received a report of theft on Wednesday.
“The theft is believed to have taken place at around 1.35pm that same day,” she said.
“A woman had approached a residential address in Stephendale Road, Fulham, and removed a window box containing plants and took it away with her.
“No arrests. Enquiries ongoing.”