Well, prior to that, she tweeted #Memories:
"
J'adore faire du rangement et retrouver des choses que j'avais oublié" which Google translated as "
I love to storage and return of the things I had forgotten."
Then, "
Comme par exemple, Des bracelets portés par "Madonna", offert par "Maripol" à mon premier Olympia" or "
For example, bracelets worn by "Madonna", offered by "Maripol" in my first Olympia."
Then: "
Ou une lettre écrite par Mylène"
"
Or a letter written by Mylene."
So, My guess was either she was just rummaging through her treasure chest or she's trying to give us a "hint" of her return, music-wise, to the Goumandise and MCE days and probably working again with MF and LB!