Werid thing or glitch

I was doing the last part of the Norn quest line and I ran into this



I didn't know you could Deep Wound an inamimate object

because the health bar is a metaphor kind of for how much is left of the gate tihknk of it as a steel door and the health represents the integrety of the door everytime u pound it it gets weorse and worse nad deep wounds represents a large blow