Rubber Jungle Meaning

Example : 2006 May 15, Meryl Getline, "Ask the Captain: When oxygen masks mysteriously appear," USAToday.com (retrieved 21 March 2014):  By the way, when all the masks are hanging out, it's sometimes referred to as the "rubber jungle."2007 March 18, Jeff Bailey, "After service disruptions, airlines are saying they're sorry," New York Times (retrieved 21 March 2014):  From the day before, an accidental deployment of oxygen masks—a rubber jungle, in airline-speak—was discussed.2013, Jim Lewis, Short Tales by a Tall Pilot, ISBN 9781475969870, p. 89 (Google preview):  I looked back to see what was going on, and observed a rubber jungle of oxygen masks hanging from the overhead bins.