Sylvia Plachy couldn’t have been happier.

Her train from New York was delayed en route to Philadelphia, which meant that she arrived at the Arthur Ross Gallery too late to deliver her scheduled talk on her photography exhibit, “Repros.”

“I don’t like to talk,” she said about public speaking. “I get very nervous.”

And indeed, when Penn Humanities Forum Director Wendy Steiner, who served as guest curator for the exhibit, invited Plachy to say a few words during the reception for her show, the photographer said as little as possible, preferring to step into the shadow of Eugene Narmour, Kahn Professor of Music and interim director of the forum. But she did agree to talk to us a little bit about her work.

Then again, what could Plachy say about her photos that is more illuminating than the pictures themselves? They are at turns sentimental, stark and humorous, but they all share one thing in common: They speak volumes about the faces people show to the world and how the world in turn alters people’s faces.

Take, for instance, a photo of visitors at Stonehenge. In the foreground is a young traveler with a backpack and bedroll so huge that he appears to have become one of the plinths at the monument.

There are lots of illusions like these in Plachy’s work. And, she says, her subjects are unaware of the effect.

On the other hand, Plachy was certain one person knew what was happening. “I’m sure Ralph Nader was aware of where he was and what he was doing when he was in that room [in Moscow] with that painting of Lenin above him,” Plachy said of the picture she took during Nader’s visit to Russia in 1993. “He’s an American politician. They’re very conscious of what they’re doing.”