Principle behind bottle submerged in water? Consider the following diagram.

A drink bottle is placed upside down in a bowl and a small hole is made in the cap of the drink bottle. Assuming the drink bottle is filled with water, why doesn't all the water continue to spill into the bowl until the water level is equal? Shouldn't this be the case due to Pascal's law of communicating vessels?
However, in practice, the water from the drink bottle does not continue to spill and the water in the bowl maintains a constant level. If we remove water from the bowl, the drink bottle spills again and restores that same level of water back in the bowl. What is the working principle behind this?
 A: The pressure at the free surface at the top of the water in the bowl is that of the atmosphere.  If the bottle was initially filled with water, once immersed in the bowl as water flows out of the bottle into the bowl the pressure in the void space at the top of the water level in the bottle is very small; initially essentially a vacuum, but over time as the water evaporates the pressure in the top of the bottle from water vapor reaches the saturation pressure for the temperature of the water in the bottle, small compared to the pressure of the atmosphere.  The pressure at the top of the bottle is less than the pressure in the atmosphere resulting in a water level in the bottle higher than the water level in the bowl. Do a force balance on the water in the bottle to see this.
If you remove the water from the bowl, even though the atmospheric pressure on the water at the bottom of the bottle is greater than the pressure in the "void" at the top of the water in the bottle, there is a Taylor instability due to a heavier water on top of a lighter air and water flows out of the bottle; the "gurgling" of water out from the bottle allows air to enter and rise to the top of the bottle so the bottle and bowl water level become equal and flow out the bottle ceases, assuming there is enough water in the bottle to fill the bowl to the level of the water left in the bottle.
See Physics of the inverted bottle dispenser on this exchange.
