I mean, I understood the words, I didn't understand what they meant. How was she making money off the mortgages?
In fact I can't say I understood why specifically strippers came up in their conversation - they can't be the only "cash-rich" segment of the population.
She wasn't making money off mortgages.
The stripper was basically saying how easy it was for her to buy property, and how she got them at such low rates and how the mortgage brokers or bankers or anybody really didn't question or discourage her buying properties. Then Mark tried to explain that her teaser rates are going to go up 200% eventually and she won't be able to refinance, as she was under the impression it was going to be easy to do so. Then she dropped the bomb to Mark that its just not one place she bought... it was several.
That was kind of the straw that broke the camels back in Mark's mind and convinced him that she (and many many other American's) were eventually going to go under.