Oh flashbulbs, you naughty things, you.
On Tuesday evening, the Austraian attended the Tracks premiere at the Toronto International Film Festival in a hot pink Azzedine Alaïa dress that suddenly rendered itself sheer under the dazzling glare of flashes.
Beneath her frock, Mia wore a two-tone bra with rhinestone trim and matching panties.
We can't help but admire the sparkle, and we're sure Jesse Eisenberg can't either!
[Image via Getty Images.]