The Tesla boss shared the footage with the caption “Optimus folds a shirt”.
The company said its ambition for the robot is to create a “general purpose, bi-pedal, autonomous humanoid robot capable of performing unsafe, repetitive or boring tasks”.
According to a biography of the multi-billionaire published last year, Mr Musk told his employees that the Optimus robot was key to transforming the electric vehicle company into a $10 trillion company.
“The vision is for them to serve millions of households, such as cooking, mowing lawns, and caring for the elderly,” he said.
However, about 30 minutes after sharing the latest video, the SpaceX and Tesla chief shared an “important note” under the post that the footage was not entirely as it seemed.
“Optimus cannot yet do this autonomously, but certainly will be able to do this fully autonomously and in an arbitrary environment (won’t require a fixed table with box that has only one shirt)” Mr Musk said.
Users on X as well as the rival platform Threads raised questions on how the video was made if the robot’s feat was not “fully autonomous”.
“This is a video, not CG?” one user asked, questioning whether the video was computer-generated.
Some observers also pointed out a gloved hand appearing briefly in and out of the frame in the video, seemingly mimicking the movements of the robot’s hands.
“It’s just operated remotely, not autonomous. Basically the exact same way remote surgical ‘robots’ have worked for decades,” another Threads user said.
Tesla did not immediately respond to The Independent’s request for comment.
The EV company is yet to provide information about the price or release date of Optimus but in the past Mr Musk has hinted that the robot may cost less than $20,000.
At the 2022 Tesla AI Day, the Tesla titan said deliveries of the robot could take place within three-to-five years.