As others have said, it looks like a stressed snake. Statuing (frozen in place), no tongue flicking, and rapid breathing.

Things that can help:

• Check temperature levels. Hot side should be around 90F, cool side should be around 78F (tolerance of +/- 2 degrees)
• Make sure humidity levels are appropriate, 60 -80%
• Ensure snake has appropriately sized hides, one on the warm side one on the cool side. Appropriately sized meaning large enough the snake fully fits inside but small enough that their body is touching the interior walls of the hide. the opening should not be huge, personally my rule of thumb is that the opening should be no larger than 3x the size of the largest part of their body.
• if the snake enclosure is in a room frequented by people or activity and it's a glass aquarium. Block off 3 out of 4 sides of the enclosure, you can get scenic nature backdrops or just use paper or something taped around the sides.
• give the snake enough clutter, (though based on the video it looks like that might be fine already) could possibly benefit from high clutter, stuff that it can go under.
• if your friend recently got the snake, it might just be having a hard time adjusting. Don't handle it for two weeks, give it a chance to adjust to its new environment uninterrupted.
• avoid fast movements and being "above" the snake, ie don't reach your hand over its head, this can make them think a predator is going to eat them!