This is an experiment to see if people will treat a food item more preciously if it is presented in a way that is aesthetically pleasing. Food establishments often use prepackaged butter as a way to easily serve customers AND portion the butter, so there is reduced food waste (and cost). However, it is at the cost of more plastic waste.
The theory is that users may use less butter if it is aesthetically pleasing. On many occasions, items that are well crafted and/or crafted from quality materials receive better care. If less butter is used, there is more of an argument for "well crafted" butter pats to be used, instead of the plastic packets of butter.