Chris Paxton, an AI and robotics researcher who leads AI at Agility Robotics after prior roles at Meta FAIR, posted a tweet containing a video attachment. The video depicts a gray quadruped robot fitted with yellow-and-black wheeled feet. A white and yellow box the available reporting labeled RIVR on both sides rides atop the robot. Footage shows the machine climbing and descending snow-covered concrete stairs while gripping green surfaces. The post originates from his account on X and presents this specific sequence of the robot moving through the winter environment.