It could have been the shimmering outfits - or the fact they are looking considerably older than when they first burst youthfully onto the pop scene.
But the Spice Girls were yesterday being dubbed the Golden Girls as they sang on stage together for the first time in nearly a decade.
Gone were the platform boots, the eye-popping outfits and the “accidental” flashing of underwear.
Instead the five women were clad in sleek gold outfits by designer Roberto Cavalli.
The five - made up of Victoria Beckham, Geri Halliwell, Emma Bunton, Melanie Chisholm and Melanie Brown - were said to have been nervous before their comeback gig in Vancouver last night, the first of a 40-date world tour.
A spokesman for the band denied suggestions that they were not singing live or that they used backing tracks.
He said: “All of the girls sang live.
“There is a click track for the band to keep them in time, which is standard, but all of the girls’ vocals were live.”
David Beckham made a surprise appearance, seeing his wife Victoria for the first time in three-and-a-half weeks after jetting back from New Zealand where he was on tour with his team LA Galaxy.
Posh Spice, who posed for her male dancers who were pretending to be paparazzi during the performance, confessed she was anxious about her husband seeing the show.
Mrs Beckham said: “David turned up today but he hasn’t been at any of the rehearsals because he’s been away working so I’m nervous about what he’s going to think about the show.
“He’s not even seen any of the costumes.”
He bought each Spice Girl a gold bracelet to celebrate the reunion.
Despite rumours of rows in the lead-up to opening night, the five held hands and embraced each other throughout the show, with Geri and Victoria going to great lengths to display their affection towards each other.
Geri, who had said in a press conference before the show that she might consider living in Canada, shouted out: “This is our first time back together and you’re the first to see it. We love Vancouver.”
Emma told the audience: “It’s great to be back.”
Mel C, who sang her solo track I Turn To You, was grinning throughout the set. Earlier she had spoken about being reluctant to do the tour when first approached.
She said: “I won’t lie about it - I was scared.
“I was nervous about it. But I feel there has been a change of feeling in the world.
“I feel the feeling for the Spice Girls has changed, and it’s been a natural thing.”
Last night their two-hour concert was set to include 22 songs and involve multiple costume changes.
Miss Bunton, 31, previously said the band was having the “best time”, adding: “It is very emotional to be back on stage together. It evokes a lot of memories.”
More than 15,000 fans watched on as the group were joined on-stage by a team of male dancers who dazzled the audience with breakdancing, ballroom moves and acrobatics.