Both stars are currently rocking peroxide bleach jobs and both are notorious for their extreme approach to dressing (and undressing) in public.
However, since one of them is playing the grandma role in Mamma Mia 2, it looks like that is it is Cher behind those shades.
Of course, the legendary performer shows no signs of slowing down or dialling down the diva moments at the fiercely fit age of 71.
She could probably even pull off Gaga’s skimpy denim shorts outfit if you gave her a motorbike. As it is, her entrance in the musical sequel is just as dramatic as you’d expect.
As Amanda Seyfried’s Sophie and all her friends and family (with one major exception, but more on that later) prepare for a party, Cher steals the show and shows she has the outfit and answers for any occasion.
Sophie is not impressed and says: “Grandma you weren’t invited.”
Cher bites back: “That’s the best kind of party, little girl, ” before breaking in a stirring rendition of Abba’s Fernando.
But where is Sophie’s Mum, Donna?
After the first trailer landed, fans started worrying that Donna was dead. Meryl Streep’s lovable hippy is never shown interacting with any other character, leading many to think she will only be shown in flashbacks.
One fan posted: “Wake me up when someone from the Mamma Mia 2 crew confirms the trailer was poorly made and Donna is obviously alive.”
Another added: “Why on earth did you kill off Donna?!?! She was the best part of the movie… We waited 10 years for a sequel, only for this to happen, I’m inconsolable. “
From the evidence of this latest trailer it looks like they might be right…
Mamma Mia 2 is out on July 20, 2018.