three-deep

the New York TimesにあったファッションデザイナーZac Posen氏に関する記事から。「深い」という意味で知られるdeepですが，アメリカ英語で「…列に並んだ」というように「列」を表すことができます（『プログレッシブ英和中辞典』小学館）。ここでは「3列に並んだパパラッチたち」と解釈できます。（Koyamamoto）

From the Red Carpet to the Bottom Line
This February, Zac Posen went to the Oscars. Though he had been in Los Angeles and gone to the parties surrounding the awards several times over the last decade, the designer had never attended the actual ceremony at the Kodak Theater.
Yet Mr. Posen decided not to make his way down the red carpet, where the paparazzi were lined up three-deep.
“I walked on the side part,” he said about a week ago, sitting in his studio on the edge of SoHo and TriBeCa. “I didn’t think it was appropriate for me to be promoting myself as a celebrity. I haven’t worked on a film project.”
http://www.nytimes.com/2013/06/02/fashion/zac-posens-path-from-the-red-carpet-to-the-bottom-line.html?ref=global-home&_r=0