Possible Clues:

• Tiny cake, maybe
• 'Sweat smile' or 'money-mouth face,' e.g
• Symbol such as Thinking Face
• Tiny birthday cake, perhaps
• Texter's icon
• Image in a text
• Smiley face, maybe
• Smiley face or frowny face
• Heart-eyes face, e.g
• Funny face?