Why does my medium cup of coffee taste better than a small?

Most mornings I pick up my coffee from the dunkin donuts store front in Hamilton nj before I alight my morning train. Depending on my mood I order either a medium coffee light and sweet or a small one light and sweet ( as well ) every time I drink coffee I meditate on the exactitude of proportions that may result either in the perfect cup or a not so perfect cup. Today it occurred to my that my chances for a perfect cup were more likely when I ordered a medium cup than with a small cup.

Most of the time, the small coffee appears too milky to the palate or too sweet ie too light or too sweet. I even tried altering my requests ( one cream two sugars, milk and sugar combo) but the results were farther from the light and sweet versions.

I have one hunch if I try to visualize how they've set up the kitchen behind the counter. Using a squirt mechanism they are able to quickly output requests. If it's the same amount of cream and sugar that gets added to the coffee, then there's a greater ratio of milk to sugar that's added to the smaller cup of coffee than the larger one. I wonder if the I interface that's designed for the squirting accounts for this subject to my correctness of my hunch.

For a great cup of coffee for me, consistency and familiarity of my sip trounce elevated taste or flavor. It is this one thing or two that I look for ( and suspect most others do as well ) in their experience of coffee.