There is definitely a distinction between being “nice” and being “kind,” as this Lifehacker piece notes:
Think of kindness as the act that accompanies (or replaces) your words. It’s silently helping a struggling mom of three kids unload her groceries into her trunk, rather than smiling and saying, “You’re doing a great job, mama,” as you breeze past. It’s bringing a pot of soup to your sick friend, rather than sighing sympathetically and saying you hope they feel better soon. You’re kind if you shovel your neighbor’s car out from under a pile of snow, stop to help a stranger change a tire, or pause to give an obviously lost person some directions—even if you’re not the type of person to bother saying “Bless you,” when someone else sneezes.