Others understand the word in an opulent light as in tasteful richness of design or ornamentation "the sumptuous elegance of the furnishings."
The proof of a mathematical theorem is considered to have mathematical elegance if it is surprisingly simple yet effective and constructive; similarly, a computer program or algorithm is elegant if it uses a small amount of intuitive code to great effect.
In engineering, a solution may be considered elegant if it uses a non-obvious method to produce a solution which is highly effective and simple. An elegant solution may solve multiple problems at once, especially problems not thought to be inter-related.
Visual stimuli are frequently considered elegant if a small number of colors and stimuli are used, emphasizing the remainder.