"That smile though" is a colloquial expression used to compliment or comment on someone's smile. It is often used when the speaker finds the person's smile particularly attractive, charming, or endearing. The word "though" in this context adds emphasis to the compliment, suggesting that the smile stands out or is notable in some way.
For example, if someone posts a picture on social media with a beautiful smile, a friend might comment, "That smile though ?" to express admiration for the person's captivating smile.
It's a lighthearted and positive way of acknowledging someone's pleasant facial expression and is commonly used in informal conversations, especially on social media platforms.