For Tallulah Willis (pic), an Instagram throwback about her father, Bruce Willis, evolved into a public conversation about her experience with autism.

Tallulah, the 30-year-old daughter of the Die Hard star and his ex-wife, actor Demi Moore, revealed over the weekend that she was diagnosed with autism last year. On Instagram, she posted a video of her younger self in her father's arms as he answers questions at a red-carpet premiere. In the clip, the younger Willis runs her hands over her father's head, touching his ears.