Kelly, a representative from Death Wish, discusses their early adoption of SMS and how they initially used it similarly to email marketing. Over time, they recognized the opportunity to develop a more authentic and engaging tone unique to the SMS channel. This tone is described as direct, humorous, and sometimes sarcastic, with a focus on being engaging and real. They discuss the importance of maintaining consistency across channels while still adapting the tone to suit the medium's constraints and strengths. Additionally, they highlight the need for messaging to be impactful and engaging in the limited space available in SMS, contrasting with the more detailed approach of email marketing.