Pablo Picasso’s birthday was coming up and Veronica Watson wanted to celebrate. She was standing in her workshop at the Legoland Discovery Center in Yonkers last October, where she serves as the master model builder, and was scanning online through the artist’s paintings.

She settled on “Guernica,” since she thought the antiwar mural would look cool in Lego. She found a picture of the painting and, working from the upper left corner, began to recreate it — brick by brick.

“I’d do a little bit, walk away, come back, look at it, and then add to it,” Ms. Watson said.

Of all the jobs held by recent graduates of the Urban Design and Architecture Studies program at New York University, Ms. Watson, 23, most likely has the most unusual one. She cleans, repairs and maintains existing Lego structures and inspires visitors with her own fantastical creations. But her projects are more than children’s playthings — they are true works of art.

Picasso’s “Guernica” is a case in point. Within hours after she began her replica, her co-workers — some had called her crazy for taking it on — were amazed at the re-creation. Ms. Watson, a self-described kid at heart, shrugged off their astonishment, even if she felt a little giddy.