Thai massage is a combination of Buddhist meditation traditions, Indian yoga traditions, and Traditional Chinese Medicine. Unlike general massage techniques that focus on body muscles and fascia, Thai massage targets the "Energy Body" - the holistic integration of a person's spirit and physical body - through physical contact with the body's energy lines (Sen lines).
Specifically, Thai massage therapists (especially those practicing the Lanna style) use mindful qualities to activate the energy body through rhythmic pressure, complemented by yoga stretches and guided breathing, leading the recipient into a state of mindfulness. The recipient, by focusing on their own breath and the tactile sensations created by the massage therapist, is able to return to the present moment, achieving both physical and mental relaxation.
As a practitioner of insight meditation, in my view, Thai massage is an extension of meditation practice. A focused and complete Thai massage session is like the massage therapist guiding the recipient on a walk through a forest, providing excellent relaxation and state enhancement for both parties. Thai massage therapists need to have a foundation in meditation practice to be able to evoke positive energy from the recipient's body.