Maybe the terms heavy and light are meant to denote quantity in this instance o.T.

Heavy seems like it is used as "a heavy concentration of" rather than heavy meaning having a lot of weight - and vice versa with the term light.

F.W.I.W., I like the word dollop, though I never really use it. Strawberries and cake are meant to be covered in liquid whipping cream - dollops are just not enough.