From a quick glance at an object, the brain processes a large amount of data unconsciously. It focuses in on the few factors that matter, making rapid judgments. They may relate to factors such as quality, patterns, relevance, and others. These snap judgments can sometimes be just as good as those made slowly and deliberately.
You can tell a lot about a person's personality by looking at their living or working environment. For example, you can pick up on behavioural residue (dirty laundry, neat filing system), identity claims of how they would like themselves to be seen by the world (framed degree).
Thin-slicing can be led astray by emotions, stereotypes, and prejudices. For example, judging people by their appearance, that because they are distinguished-looking they must be intelligent. Also, when highly excited, a person may become 'mind-blind, where capacity for thought can be reduced. In these cases, it is useful to resist snap judgments rather than relying on them.