Why is Chloe picking out grapes from the lowest hanging bunches for the workers?
Are they perhaps the choicest? (Unlikely)
Are they the most sour for lack of sunshine? (Possible)
Is she keeping them from babies? ( 
)
I came across this line, reading Rouse’s pastiche of it to my daughter the other night, and wondered the same thing. It turns out that the lowest grapes are the ripest and sweetest, due to reflection from the earth.
That choice may have been a reflection of a flavour preference for the wine, or at the very least, that decision would have had an inadvertant effect on the flavour of the wine. I’m not suggesting that the vines in the story were Cabernet Sauvignon grapes, but if they were (and the colours mentioned throughout the text suggest that they may have been a related variety), then the progression of flavorants throughout the ripening process, might be like this one in figure 5 of Bisson (2001).
Bisson, L. 2001. In search of optimal grape maturity. Practical Winery & Vineyard.
July/August. Pp. 32-43.