April Masini, an online advice columnist at AskApril, shared her expertise with The Wall Street Journal on proper gym etiquette in the age of smartphones. She highlights how behaviors like taking mirror selfies and unintentionally including others in photos can cross personal boundaries in shared spaces. Masini stresses the importance of being mindful, respectful, and aware of others, even in casual environments like the gym. Her insights frame modern etiquette as a balance between self-expression and consideration, where respecting privacy helps maintain a comfortable and respectful community for everyone.