To pose difficulty

Does "The difficulty these images and performances pose to the viewer" mean "The part of these images and performances that makes the viewer unhappy"? Actually, I want to know if "to pose difficulty" here means "to make unhappy"?

Context:

In 133 Persons Paid to Have Their Hair Dyed Blonde from 2001, realized at the Venice Biennale, Sierra hired a large group of specifically dark-haired migrant workers, most of whom he recruited in the street in Venice where they worked as illegal vendors, to have their hair dyed a straw-colored blond. He then turned over his exhibition space to these same workers, who continued to sell their merchandise, mostly fake designer handbags, within the gallery spaces of the Biennale. A quick perusal of the documenting photographs of these works, particularly from the 2001 Venice performance, confirms that many of these workers were dark-haired and people of color, of African or Bangladeshi ethnicity. The difficulty these images and performances pose to the viewer is their stark staging, within the confines of art, of the labor of lower-salary and minority workers. As many critics have observed, Sierra’s position on the matter of the exploitation of migrant labor is ambiguous or “amoral,” though one has the general sense that Sierra believes that capitalist exploitation of the immigrant working poor—who are often ethnic minorities—is a bad thing.