As mentioned in a post earlier today, a platoon size element is shown assaulting a Ukrainian occupied trench.

In this footage specifically, we see more of the "aftermath" of the assault, as in the previous footage we witnessed an intense firefight between the opposing forces. As the man behind the camera pans around, Javelins, ammunition, and even identity cards are located within the trenches. It would appear whoever previously occupied these left in a hurry or suffered fatal consequences during their defense.