In the video, a person is seen holding a smartphone with its back cover removed, exposing the internal components. The person is holding a battery in their hand, which they then proceed to insert into the phone. The battery is black and rectangular, with a white Apple logo on it. The person carefully aligns the battery with the corresponding slot in the phone's internal framework and pushes it down until it clicks into place. The video provides a clear view of the battery being inserted and the person's hands performing the action.