This theoretical review proposes a novel framework elucidating how balanced power relationships in painting therapy facilitate self-reconstruction among older adults. Central to this framework is the activation of metacognition—comprising knowledge, experience, and monitoring—through three therapeutic stages: Externalization, Dialogue, and Reconstruction. We argue that traditional authoritative therapist roles inhibit older adults’ creative autonomy and reflective capacity, whereas collaborative, balanced relationships promote a shift from first-person emotional immersion to a third-person observational stance, thereby enabling schema revision. The core mechanism posits that power balance activates metacognitive processes, which in turn mediate positive therapeutic outcomes. Practical implications are substantial, necessitating a shift in therapeutic focus from technical instruction to relationship management, and corresponding adjustments in counselor roles, intervention techniques, and self-cultivation. This review integrates neuroscientific evidence to support the proposed psychological mechanisms and offers actionable guidance for enhancing geriatric mental health services.