She said: "It was really high energy, you put the outfit on - some really amazing, beautiful, intricate, ornate pieces - and off Karl went taking photos and picking what I wore.
"There were loads of people buzzing around, music on loudly - it was all so quick! Karl's so creative. He really thinks about shapes and angles."
As well as being loved by the Chanel designer, Anna is also a hit with Gucci's Frida Giannini, who offered to dress her for her tour, and the 29-year-old singer says it is a collaboration which works well.
She told Grazia magazine: "I met her at a Gucci dinner. Wouldn't wear anything just because they were giving it to me, but I find that there are lots of Gucci clothes that suit my style, so it's a really nice collaboration."