Discrimination works in a few different ways in this text. First, Ehrenreich experiences the discrimination against the working class in a supposedly classless society. The extreme invasions of privacy put on minimum wage earners are nothing like the freedom middle class or upper class workers experience. Random bag searches, drug tests, and personality tests may be required to get a job, and at least two of those are almost certainly required to keep it, in many cases. In addition, she experiences a different attitude entirely toward herself as a minimum wage worker. The memory of working Walmart is one of the most depressing pieces of investigative journalism in recent history. She is subtly (and sometimes not so subtly) outcast from those who shop there, and looked on as a servant. This is essentially what she confronts in all her jobs.
Another example of discrimination throughout the book is gender discrimination. She faces sexual harassment and lower wages due to being female, & watches many women forced to use their sexuality just to remain on equal terms with male co-workers, or to be treated decently by male employers. This is especially relevant today, with the raging health care debate. Women can still be denied coverage due to Cesarean sections, and some insurance companies require sterilization as a criterion for coverage if one has had a Cesarean section.
Finally, Ehrenreich is not only on the receving end of the discrimintaion. She brings middle class biases to her research, & often judges her fellow workers for their perceived lack of anger at their situation. She also makes many disparaging remarks about obese people in her work as well.