"Any expert opinion of whether this a camera? Perhaps @SingaporeAir could clarify how it is used?"
The tweet generated a flurry of chatter on Twitter, with users agreeing it did look like a camera.
"What is the purpose of these cameras, and how do you store the information gathered by them? How do you notify passengers about these cameras?" one person tweeted at the airline.
Others had some theories for why it was there.
"A lot of these infotainment systems are running on Android tablets, so presumably the hardware was sourced from some vendor that thought cameras would be valued by consumers then got repurposed for aviation use," Twitter user Michael Brown pointed out.
Others reported they'd seen similar small cameras on flights with other airlines.
Eventually Singapore Airlines joined the conversation to confirm that indeed, it was a camera.
"We would like to share that some of our newer in-flight entertainment systems provided by the original equipment manufacturers do have a camera embedded in the hardware," the airline said.
"These cameras have been disabled on our aircraft, and there are no plans to develop any features using the cameras."
The airline also said the cameras were in selected business, premium economy and economy class cabins and had all been disabled, with no plans for future use.
Now, American Airlines and United Airlines, have also explained the cameras which may be seen in some of their aircraft.
According to The Independent, a spokesperson for American Airlines said the cameras have been installed by the companies that make the entertainment systems to offer passengers options such as seat-to-seat video conferencing.
But, along with Singapore Airlines, both say the cameras have never been activated.
American Airlines spokesman Ross Feinstein said cameras were in "premium economy" seats on 82 Boeing 777 and Airbus A330-200 jets.
"Cameras are a standard feature on many in-flight entertainment systems used by multiple airlines," he told the Independent.