I've seen a couple photos of pour over setups where one would have an "outer" scale that measures the input water pour while a secondary scale measures the output resultant drip.
Is there some sort of reason one would like to take the extra step and use this setup?
My only explanation I thought of would be that the person is highly concerned of the the amount to be poured to the final cup, being highly mindful of consistency...
See Acaia's stand for example with their smart scales: 
My goodness - all sorts of new gadgets to get intrigued about - and now - you have a reason to buy BOTH sizes of acaia scales! a pearl for the base and a lunar for the pot!
for me this double weighing is to check saturation of water by beans - seems like this device could make this process reuqire fewer steps.
For instance - i like to make sure i'm getting at least a 2-1 water absorption relative to weight of beans. if the taste is less rich than i'd like before adjusting the amount or grind, it's a quick check to see how much water was actually absorbed by the bean - sometimes this absorption check tells me something about the age of the beans too - if they haven't degassed long enough they seem to absorp less - and that's even if the coffee slury is well stirred/no bubble in the slury.
It's also interesting in an abstract kind of way to see how absorption differs fro same grind, amount but different varieties. etc.
It's this kind of check that let me let the coffee sit a little longer after stir before doing a pour: higher absorption seems to relate nicely to richer flavour.
At least that's what i'm finding.
thanks for sharing this trick new device.
m.c.
