You just got 3 suggestions covering the three basic choices. Here is my answer, taking into account all 3 suggestions. I and most are right-handed. If you hold a pen in writing position, in your right hand, there is only one area where the image will be seen. the other positions are covered by the writers hand. So I put the image where it will be seen...to the right of the clip if looking straight at the pen (with writing tip pointing down), with the clip directly toward your view. The logo will then be seen while writing with the pen. An exception is if the image/logo is fairly large, so as to wrap around much/most of the pen. in that case, I believe the best look is to center the image directly opposite the clip.
