The digital transformation of markets has accelerated the expansion of trademark subject matter beyond traditional word and logo marks to include sound, color, motion, shape, and scent. While international instruments such as the TRIPS Agreement adopt a flexible definition of trademarks, the doctrinal accommodation of non-traditional marks remains uneven across jurisdictions. This article examines the theoretical foundations, evidentiary burdens, and enforcement complexities associated with non-traditional trademarks. Through comparative doctrinal analysis of United States and European Union jurisprudence including Qualitex, Sieckmann, and Shield Mark this study identifies structural tensions between distinctiveness, non-functionality, and competition policy. It argues that the expansion of trademark subject matter risks over prophetization unless disciplined by rigorous evidentiary standards. Focusing on Indonesia as a representative emerging jurisdiction, the article demonstrates that regulatory ambiguity undermines legal certainty in digital markets. It proposes a five-step structured distinctiveness and representability model integrating consumer perception, technical objectivity, and competition safeguards. The article contributes to global trademark scholarship by offering a calibrated reform framework balancing innovation and market freedom.