This chart was presented to say that students from wealthier backgrounds are more likely to work part time.
But digging into the details, we find this chart is heavily skewed by combining work with “internships”.

The “internship” category is a lot of the lifting here.
First, students in wealthy households are more likely to have parents with strong professional networking opportunities, leading to good internship and work options.
Second, about half of wealthy student internships are unpaid – they don’t need the money.
Almost no low-income students take unpaid internships – they need the money from a paying job.
By combining “work” and “internship” in one chart, we see a skewed result.
Third, wealthy students are much more likely to attend elite and/or private universities with tougher admission standards. Adding an unpaid internship – especially at a quality organization made possible by parents’ connections – is said to help with that.
Thus, wealthy families encourage and link their children to “quality” options as part of the elite college/career pipeline: They are not working at McDonald’s!
A related data point is that in the 1970s, about 2 out of 3 teens held a part time or summer job and today it’s about 1 in 3. There are many reasons for that but one is many states now have age and work restrictions on youth. In my state part time job options have a lot of restrictions until age 16.