Telescoping is a technique that stresses close observation by the writer. The sentence works like a telescope. The Telescoping sentence keeps moving closer and closer upon ideas in the previous clause.

"The girl sits on the bench."

Telescoping "The girl" : "The girl, wearing a red dress, sits on the bench."

Telescoping "the bench" : "The girl sits on the bench, which is placed in the Central Park of New York."

Telescoping "sits" : The girl sits, crossed legs, on the bench"