The cows are a (bad) metaphor for the means of production, obviously. The metaphor sneakily puts you in the shoes of a capitalist and, whoa, it turns out capitalism is good when you are one of the few it benefits.
I can't believe I was once taught this bullshit in school.
It also distorts perceptions of inequality by implying that just two cows makes you a rich person who stands to lose under socialism. A more apt metaphor would be
Nah its a great metaphor. Rich people own cows (the means of production) poor people get some milk (if any)