The Mean Girls actress wore the demure knee-length frock as she attended a photoshoot in West Hollywood.
Her patent court shoes and smart black handbag suggested she was going for a ladylike look.
Unfortunately, the effect was ruined by her free-swinging breasts — which looked like they were trying to escape from the arm holes of her dress.
It’s not the first time Lindsay has nipped out without her underwear and she is often snapped in attention-grabbing attire that does little to hide her assets.
But the 25-year-old has been steering clear of her trademark skimpy outfits as she prepares for her role as Hollywood legend Elizabeth Taylor in upcoming biopic Liz & Dick.