directions on the sky

I wrote code to overlay arrows on pretty pictures, pointing from one object to another. Here's an obvious realization I had about it: If object positions are given relative to us (eg, in RA,Dec,distance), then their radial distances from us do not come into the directions of the arrows at all. To test my code, I made the arrow pointing from Willman 1 to the UMa dwarf (Willman 2). It is shown below (on a weird coordinate system because I was stress-testing my code).