Most presentational refers to something that is characterized by a high degree of formality, showiness, or display. The word "most" in this case implies an extremely high level of presentational emphasis. Therefore, antonyms for this phrase could include understated, humble, modest, subdued, unobtrusive, or simple. These terms suggest something that is less showy or less focused on presentation. In a different context, the antonym for most presentational could also be informal, casual, relaxed, natural or spontaneous. These words denote a more laidback, informal or relaxed atmosphere, which is different from the formal and presentational tone suggested by the original term.