The colors are nice, shooting angle good,exposure OK, but it is tough to make this one work because of the overlap and the head positions.
Preening pictures generally work best when the head is parallel to the image sensor.
Overlaps can work, but generally they have to have matching head and body angles, and the almost universal issue of DOF with two birds, has to be worked around. Generally, you want the focus to be sharp on the front bird, as you have.
Loons can be a bit of a challenge to approach. Much easier to get in close from the water side, they seem to tolerate our presence and seem less threatened. All of my loon pictures on BPN were taken from boats, either a pontoon boat or my Lund.
Another alternative would be a floating blind of some type, but they often move more or less constantly as they feed, so can be a issue to keep up with them!