[markdown]

I assume you are being sarcastic.

Drinking vessels come in all different sizes, from dainty little tea cups to mugs that hold an entire litre.

Measuring the milk requires both measuring the steep time exactly, and using a separate measuring cup. This wastes time and adds unnecessary cleanup.

Stirring as you add milk to the tea allows you to tell exactly the right amount for that cup (and for how long the tea was steeped) based on the colour of the beverage.

[seoulmetro]

Measure is not being used as a literal verb. It's being used as an approximate measure. The same way we measure how much time we spend doing a task without a clock.

[markdown]

No it's not. Read again

> measure a specific amount of milk in isolation than to eyeball how much of it you've just added to something else

[seoulmetro]

Yes, it is. They are measuring the milk in isolation, which in this instance means to pour (and measure with your eyes) as it fills the empty container before the tea. Whereas you can't really measure how much the volume is changing (eyeballing) in isolation.

Think of it as the difference between measuring a liquid in a container and eyeballing a liquid in another liquid.