Target and Implied Target.
This is how it works now;
If you have no target, there shouldn't be a target window. If you have a target and your target does not have a target there will be a target window with one health bar and the name of your target will hover over that window. If your target has a target, You target will shrink to just over half of the target window and the remaining part of the target window will be populated by the implied target information that looks just like the target information just a little bit smaller in width.
From looking at Raesoth's screen shot, it looks like something is amiss, I'll look into it..
The screen shot on the left is how it should look with out his target having a target.