!Disclaimer! This is just my own personal experience, being both a "Trader" and an "Aldanite", as well as recently just a "Regular Jammer".
By my definition, and instead of calling them "Jammers Who Don't Trade", I will call them "Regular Jammers" because it's just easier. I meant no offense calling anybody "Regular". If your personal experience of being either a Trader or a Regular Jammer has been or is different, please don't go crazy on me :)
The first difference between a Trader and a Regular Jammer is their Dens:
This is a regular Jammer's den. Notice how it doesn't really have many den betas in it, and is very homely, much like a modern house (excluding the ice mirror and the gigantic edible furniture).
This is the Trader's den. Notice the good deal of den betas as well as the flooring. It's still very well furnished, but may have a slightly more ethereal feel to it.
The second difference is how they make their looks.
The regular jammer will probably make the outfit that suits the animal, the character, or the vibe the best.
I've noticed that Traders tend to like to show off their rares, sometimes they will picks a colour scheme like this one (red), or they'll just put all of their rares on one look (ew).
The next difference is in the buddy system. The trader jammers will probably have a buddy list somewhat like this, because they buddy people who are either rare or you have previously traded with. A small portion will probably be your friends though, because AJ is just boring without them.
I'm way too tired to continue this list right now, so I'm just going to leave it at that. I also just realized that I probably just offended a bunch of people, another reason why I will stop.
Have a great day :D