Hi Anamoslema,
Well, I don't know if you heard the saying: “The grass is always greener on the other side”, the other side represents (a) different individual(s), and grass represents numerous of personal items and aspects in comparison that either is in possession of, or has under control, greener simply represents better.
As you probably know, grass needs mowing, mowing means work, mowing could represents all kinds of work, but always relates to personal effort. That's why that example statement, you question about, refers to doing work = working. This statement simply means that one is not paying attention to how well or what the other is doing, but takes the words grass and greener and uses this in the same context of that saying, hence 'yours is greener' which is inconclusive of being a fact, because the person making that statement simply doesn't notice that as a fact, he/she is (too) occupied.
I think, that means: I don't care how wealthy you are. I am just minding my own buisness.