"The Wolfenstein Challenge" - "The Trap" [2nd campaign, 2nd mission]

by the way, could you tell me something about this campaign – what is the purpose of the animation resembling the “Weakness” spell in the mushroom moss on Wolfenstein (it’s near the sawmill and the chest in the northern part of the underground map)? We break through the guards, head towards the chest, and halfway there, this effect appears, as if from an exploding green vial with the Weakness spell. What does it do? I thought it weakens stats, but it doesn’t seem to have any effect.