The older ones usually make you wait for a minute or two before the door is unlocked. I have one in my current apartment that doesn’t do that, but I’ve tried it a couple times and it does spill some water when you open it.
With top-loaders, you don’t even have to pause, the lid is always open; and the water stays inside, obviously.
With both my 2006 Whirlpool front loader (trash) and 2022 LG front loader (excellent), the duration from when you press the "pause" button to when the agitator stops and the door unlocks is approximately one second. No water is spilled.
How do you do that without the water spilling out? Or do you mean waiting for it to drain, opening it, and then refilling (along with more detergent, having wasted the previous dose)?
The water level in a front loading washing machine is lower than the door seal. The seal only contains splashing water from the agitation. You hit the "pause" button, it stops agitating and unlocks the door, you throw your skidmarks in the washer, you close the door and press "start".
Since gravity continues to act in a downward direction, yes, the water stays pooled at the bottom of the drum and does not teleport upwards and outwards.
