How to Talk About Pieces of Art
A lot of contemporary art exists to challenge established notions. So it's best to take stock of whatever beliefs you hold beforehand and then note which of them have been challenged by art throughout the week. Discuss those challenged notions afterward.
If you don't understand a particular work at all, it's likely attempting to challenge some notion about art itself. Dismiss the piece as "indulgent" and steer the conversation toward work that challenges notions with which you're more familiar.
If something reminds you of a penis, it probably is meant to remind you of a penis. Yet it is considered impolite in most corners of the art world to bluntly state so. Instead of saying "Wow, that looks like a giant dong," try something like: "The phallic implications of this work are quite confrontational, don't you think?" Art people love talking about dicks as long as you call them "phalluses."
Art people also love the word "juxtapose." Look it up in the dictionary and be on the lookout for various examples of juxtapositions throughout the week. Then say, "That's an interesting juxtaposition." Your conversation partner will nod, "Indeed."
Other words to add to your vocabulary: deconstruction, approach, visual lexicon, aesthetic, gestural, transverse, balance, displace, structuring, and space (but not when referring to the outer variety). The greater number of those words you use in a sentence, the less likely it will be for anyone, even art snobs, to understand what you're saying, but they will be left with the impression that you certainly do.
For example, say things like, "I enjoy how the artist approaches the concept of space by creating a visual lexicon of gestural marks resulting in an uneasy balance of the whole piece," instead of, "So this guy just put a bunch of random brushstrokes on a canvas and called it art? You gotta be shitting me."
Remember, if you're not sure how to refer to a work that's not two-dimensional but not a sculpture, just call it an "object." You would think the art world would come up with a better term for this, but it hasn't.