But the photo, which has grabbed more than 234,000 likes on the social network, drew the attention of the Thai authorities, and led to the arrest of the two men who helped facilitate the photo op.
Conservation groups have struggled to combat the slow loris's reputation as a cute pet, especially as YouTube videos such as "Slow loris eating a rice ball" and "Slow loris loves getting tickled" up the demand for the creatures.
Wildlife traders capture the endangered mammal, and, in order to make them safe to sell as pets, extract their poisonous front teeth. The process can cause significant pain, infection and even death, and traffickers often keep them underfed or take them from their parents too early, causing additional health and developmental problems.
The two animal traffickers arrested, Passakorn Janpakdee, 20, and a 16-year-old Bangkok teen, face penalties of 40,000 baht ($1,276) and four years in prison.
“I think the penalty is strong enough because the touts’ faces keep changing -- it is not always the same person being arrested, which means many of them are too scared to do it again,” said Patong Police Deputy Superintendent Pratuang Polmana.
"We will continue this crackdown on loris touts until this disgraceful business is totally eliminated from Phuket," added policeman Tawatchai Srimai.
Thai authorities said they were grateful to Rihanna's photo that brought their attention -- inadvertent or not -- to the dealers at a Phuket nightclub. They say they have struggled to effectively end the wildlife trafficking, claiming the smugglers use a network of spies to alert one another to police raids.
The slow loris photo was not Rihanna's only controversial post: She later posed with a herd chained up elephants, earning criticisms from wildlife advocates.