The famous flash of lightning across David Bowie’s closed eyelid was a tiny emblem gracing the rock star’s cheekbone until the celebrated photographer Brian Duffy stepped in. “He told the makeup artist ‘No, no, not like that’,” said the photographer’s son, Chris. So Duffy grabbed some lipstick to draw an outline of a much bigger flash … and Aladdin Sane was born. The photograph is the centrepiece of an exhibition celebrating the 50th anniversary of the 1973 Bowie album that was released with 100,000 advance orders, taking it straight to No 1. Duffy’s image became “the Mona Lisa of pop”, according to his son, who curated the exhibition at the Southbank Centre in central London and has written a book, Aladdin Sane 50: The definitive celebration of Bowie’s most iconic album and music’s most famous photograph. Camille Paglia, a US feminist academic, described the picture as “one of the most emblematic and influential art images of the past half-century, reproduced or parodied in advertising, media and entertainment worldwide”. Speaking to the Guardian on the eve of the exhibition’s opening, Chris Duffy said that for his father it was “just another job”. He added: “I don’t think any artist gets up in the morning and thinks I’m going to create a piece of brilliant art or a cultural icon. It’s all about timing. A lot of things came together at the right time to produce this.” Bowie, morphing from Ziggy Stardust, his previous persona, to Aladdin Sane, insisted on a lightning flash. “The image asks more questions than it answers: many dissertations have been written about its meaning,” Duffy said. “Bowie was very clever at putting something out there, and letting everyone else come up with some kind of theory on it.” The shoot itself lasted less than an hour. The film was then sent for commercial processing. “There were no instant digital images or Photoshop then,” he said. “It’s extraordinary how it has lasted and been endlessly reworked. Wherever I go in the world, it’s always somewhere on a T-shirt.”. In the early 1970s – a time of industrial unrest and “general dystopia” – Bowie’s innovative music, extraordinary personas and sexual ambiguity were a “complete revolution”, he said, adding: “The flash became a symbol for a new generation to grab hold of.” The exhibition is among a number of events at the Southbank Centre to mark the album’s anniversary, including live music, talks and poetry. Musicians Anna Calvi, Jake Shears of the Scissor Sisters, Tawiah, Roxanne Tataei and Lynks will pay tribute to the pop legend by performing the album’s 10 tracks, which include hits The Jean Genie and Drive-In Saturday. The National Poetry Library has commissioned 10 poets to write new verse in response to the album’s tracks that will be presented live on stage. Mark Ball, the Southbank Centre’s artistic director, said: “The Aladdin Sane album cover portrait is considered to be one of the most influential pop culture images of the past half century, and the music remains fresh and contemporary, so we wanted to recognise this major anniversary and reflect on the album and its artwork’s enduring legacy. “It’s a work that continues to inspire today’s contemporary artists and the gender fluidity of the images still resonate deeply in queer culture in the UK and across the world.” Bowie performed at the Purcell Room at the Southbank Centre in 1969, and later curated Meltdown, an arts festival at the Festival Hall. Bowie died of cancer in 2016, at the age of 69, leaving 26 albums that inspired a generation of aspiring rock stars. Duffy, who vividly documented the swinging 60s with his fashion and pop photography, died in 2010.