You can only see traffic on the Nav display that TCAS decides may become, or has become, a potential threat. All you see are the point position, and digital numbers showing how much higher or lower they are than you, and if they are changing altitude, an up or down arrow next to the altitude differential reading. nothing else. Normal displays only indicate threats within a band of 2000' either above or below. Some sets have a switch up or down that will expand the indication band to within 7000' above or below your current altitude, but this is not normally bothered with.
In practice, as only potential threats are displayed, you only see aeroplanes within a short range. On parallel courses, only traffic within a very few miles is displayed. opposite direction traffic 1000' above or below can be displayed 40 miles or so away. So what the pilot sees is a cloud of aeroplanes around him in close range all going the same rough direction, and nothing in the rest of the massive Nav display, and the occasional opposite direction shooting down from ahead at high speed. It gives the feeling that you are in a formation of aeroplanes aall going the same way, with nothing else about.
Would prefer minimal information to locate traffic: Direction/range/altitude differential/ passing in front or behind/type.