241543903 (a.k.a “Heads in Freezers”) is a numerical keyword associated with a photo meme that involves people taking pictures with their heads in the freezer & sharing them online. By tagging a series of image files with a cryptic number, a high level of search engine optimization can be easily achieved. As a result, typing “241543903” into image search engines like Google Images successfully yields pages after pages of pictures showing people’s heads in freezers.
In 2009, David Horvitz started the “Heads in Freezers” meme. Participants took photos of their heads in freezers, tagged them with “241543903” and uploaded them to social media sites like Tumblr.

“The Boeing X-45 unmanned combat air vehicle is a concept demonstrator for a next generation of completely autonomous military aircraft, developed by Boeing's Phantom Works. Manufactured by Boeing Integrated Defense Systems, the X-45 was a part of DARPA's J-UCAS project”. – Wikipedia

Photo: Two X-45A Unmanned Combat Air Vehicles (UCAV) are shown to members of the news media July 11, 2002 at Edwards Air Force Base, California. The X-45A, developed by The Defense Advanced Research Projects Agency and the Boeing Company, is the first unmanned system designed from inception for combat missions. (Photo by David McNew/Getty Images)

Salt-resistant plants grow in sand made up of small fish bones on the shore of the Salton Sea before sunrise in an area where a controversial development would create a new town for nearly 40,000 people on the northwest shore of the biggest lake in California, the Salton Sea, on March 21, 2012 south of Mecca, California. (Photo by David McNew/Getty Images)

Bar Convent employee Lauren Masterman relaxes after cleaning a historic George and Arthur Maw tiled floor created in 1867, one of only two surviving examples of this assemblage of tiles, at England's oldest living convent Bar Convent on October 13, 2020. Visitors to the convent are being invited to follow in the footsteps of residents from the last 150 years and enjoy the historic space decorated with rare 19th century floor tiles. (Photo by Danny Lawson/PA Images via Getty Images)

“Secrets of the Whales”. Skerry’s photographs celebrate the lives and culture of whales, illuminating recent research and their diverse behaviours. His latest work focuses on four key species: sperm whales, humpbacks, orca and beluga whales. Humpback whales bubble-net feeding off the coast of Alaska. They work cooperatively to feed on herring by blowing a perfect ring of bubbles underwater to form a net encircling the fish. The whales then swim up through the centre of the bubble net with their mouths open. (Photo by Brian Skerry/National Geographic Photo/Visa pour l'Image)

A man distributes bread to Burka-wearing Afghan women outside a bakery in Kabul, Afghanistan, Thursday, December 2, 2021. According to U.N. figures from early November, almost 24 million people in Afghanistan, around 60% percent of the population, suffer from acute hunger, including 8.7 million living in near famine. Increasing numbers of malnourished children have filled hospital wards. (Photo by Petros Giannakouris/AP Photo)

Nor “Phoenix” Diana, 20, female wrestling champion from Malaysia and the world's first hijab-wearing professional wrestler makes her debut UK match at «Wrestle Queendom 3» tournament organised by Pro Wrestling EVE in West London, England on January 11, 2020. The Phoenix takes on British professional wrestler Zoe Lucas – winning the match after forcing Lucas into submission. The Malaysian Wrestlecon Champion used to compete in a mask to avoid being recognised. (Photo by Guy Corbishley/Alamy Live News)

Soyuz MS-12 spacecraft with crew members of Expedition 59/60 Russian cosmonaut Alexey Ovchinin, NASA astronauts Christina Koch and Nick Hague lifts off from the launch pad at the Russian leased Baikonur cosmodrome, Kazakhstan, 15 March 2019. Hague, Koch, and Ovchinin will spend six-and-a-half months living and working aboard the International Space Station. (Photo by Sergei Ilnitsky/EPA/EFE)