Implies the speaker is emotionally affected by the subject's actions, and can feel hurt or let down. His mother's reproachful eyes told him he'd crossed a line.
Pro Tip 2/3
Beyond Words
'Reproachful' can be conveyed through body language, not just spoken or written words. A silent, reproachful stare was all she offered when he arrived an hour late.
Pro Tip 3/3
Cultural Sensitivity
Some cultures may consider a reproachful attitude disrespectful, especially towards elders or superiors. In his community, giving a reproachful reply to an elder was unthinkable.