A configuration or pattern of elements so unified as a whole that it cannot be described merely as a sum of its parts.
A great word that has particular significance when you are talking about brand design. A well conceived and executed brand vision is truly a gestalt. When it works together it is stronger than adding together the sum of the parts. The term is appropriate for any successful design from visual to industrial or interior, in art and photography.
Definition courtesy of: wordnetweb.princeton.edu/perl/webwn