Her favorite piece, which I also quite liked, was Liu Ye's Gun:
(I think achinhibitor was right. That's a scope.)
There were also a number of posters from the Cultural Revolution on display, partly for context, as many of the contemporary pieces made reference to that period.
Whenever I think of that period I think on the one hand how much I'm glad I didn't have to live through it, and on the other how very un-Chinese my personal background is as a result. Dodged a bullet or dozen, there.