Why is there water in the public shampoo bottle in the hotel?

There is something wrong with pressing the valve. Pressure theory, Bernoulli equation and continuity equation are mainly used. From the aspects of equipment structure and knowledge of fluid mechanics, there is something wrong with the water pressure valve of the public shampoo bottle in the hotel. The bottle of shampoo leaks liquid, which may be caused by extrusion cracking. We can find an unused clean bottle and pour the shampoo into it to continue using it.