I strongly feel that a good artistic portrayal of a particular subject captures how we perceive them. It gives them the kind of elements and life, through whatever creative means work, that makes us perceive them on film or tape the way we would have perceived them in person. Or it even enhances them and how we could perceive them. Good art, good drama, good photography, etc. have or capture an impact or an essence, as well as just some sort of visual or auditory rendering of a subject.
A higher ISO setting allows you to take digital photos with quicker exposures at the expense of overall image quality. This can be crucial when taking photos at night without a tripod. To get enough light for a decent photo, you may normally have to keep your digital camera still for 1/15th of a second or longer else blurred photos may result. This is extremely difficult to do if you are holding your camera; even if you brace yourself up against a wall some shake is bound to occur.
With a higher ISO setting, you could get away in the same situation with perhaps a 1/30th of a second exposure or faster. The higher the ISO number, the faster you can take the photo, but more grain (noise) will be introduced. You should be able to get by with an ISO of 200 with medium and high-end prosumer cameras. With a digital SLR, even an ISO of 400 or 800 might introduce just an acceptable level of noise into your photos.