How does one define "stuff we don't need" ?

This chart comes from an article in the Wall Street Journal, which cites Commerce Department data on consumer spending -

A non-scientific study of Commerce Department data suggests that in February, U.S. consumers spent an annualized $1.2 trillion on non-essential stuff including pleasure boats, jewelry, booze, gambling and candy. That’s 11.2% of total consumer spending, up from 9.3% a decade earlier and only 4% in 1959, adjusted for inflation. In February, spending on non-essential stuff was up an inflation-adjusted 3.3% from a year earlier, compared to 2.4% for essential stuff such as food, housing and medicine.