Was it a glitch 😮

So I’m sitting round a customers house waiting for hubby to finish adding some fish to his huge fish tank he has to acclimatise them but I can see the reflection of the door in the black rim around the tank and all off a sudden I see the reflection kind wobble and glitch out, now no one is near the tank even if they was this tank is like 8ft long with a hell of a lot of water in it there is no way in hell it’s going to move and no one was coming in the door either but I just can’t understand what I just see there is no explanation for this.

Hubby was sitting next to me and the customer wasn’t anywhere near us..

Did I just see a glitch in the matrix 🙄