There are two reason for this. Firstly the facial structure itself is often reminiscent of ancient portraits because of it's angularity and composition of the features, like cheekbone and eyebrow arcs. Secondly their facial expression is often accepted as emotionless and severe. Their face is usually pale or bloodless.
Males often have a short haircut.
In many cases INTjs are slim. Their stomach is usually placed ahead of the chest giving them their characteristic posture. Their gait is somewhat unsure, wavering slightly. Sometimes it seems like they are not sure where they are going. This becomes more obvious in moments of excitement.