Joni Mitchell is Saint Laurent's new face, Joan Didion is Celine's - it's a big week for icons above age 70

Writer Joan Didion, 80, stars in an ad campaign for fashion brand, Celine. -- PHOTO: CELINE 
Writer Joan Didion, 80, stars in an ad campaign for fashion brand, Celine. -- PHOTO: CELINE 

LOS ANGELES - Singer-songwriter Joni Mitchell, 71, is Saint Laurent designer Hedi Slimane's latest muse, the fashion house announced on Thursday on Twitter.

The announcement of Mitchell's role in Saint Laurent's campaign came hot on the heels of the sensation caused by the news about writer Joan Didion, 80, starring in an ad campaign for another fashion brand, Celine.

Slimane not just designed a leather cape for Mitchell, but also photographed her at her home in Bel Air, said The Hollywood Reporter.

In the past year, actresses Helen Mirren, 69, and Tilda Swinton, 54, have fronted ad campaigns for beauty brands L'Oreal and Nars.