What does "just look at him, dressed in those preppy clothes" imply about the speaker's attitude?

The phrase "just look at him, dressed in those preppy clothes" suggests that the speaker is forming a judgment based solely on the person's appearance, particularly their clothing style. This judgement indicates that the speaker may hold a specific viewpoint or bias about the individual because of their attire, which is often associated with particular social or economic backgrounds. The use of "just look at him" also implies a dismissive or critical attitude, reinforcing that the speaker’s impression is superficial and based on visual cues rather than personal knowledge or understanding of the person. This focus on appearance strongly aligns with the idea of making a judgment based on how someone looks, highlighting the speaker's preconceived notions associated with "preppy" clothing.