JaBaD people: do you turn down the bottles? why???

Hi, everyone, I just remembered that a Rab that I had, turned down the bottles when they were empty. I asked for the reason once but I can´t find in my mind what he said (but it was a Kabbalah reason). I think was the kli stuff (something like the capacity of receive and give of the bottle, just like we can receive of the Creator, and give, and be like a canal, or idk….). I can´t find the explanation on the internet yet.

Can somebody explain this???

Thank you