The emote ‘Cry’ is one of several Battle Emotes that you can bind to your Ninjala character to customise their actions at set stages of a match.
By going into the Closet and then the Battle Emotes menu, you can change your victory emote, defeat emote, or how your character emotes at the start of a battle.
‘Cry’ Official Description
“A soft and sympathetic sob. Brush the tears from your face to let everyone know you’re feeling down.”
Your ninja will begin to cry, wiping tears away with the back of their hand. It’s probably aimed at being used as a defeat emote.