Not obsessive, I'd want this gone too1
Lighting is terrible so it obscures some things. But you can definitely still see that soft right lat. And, it may be as simple as that, you have poor ability to contract these muscles in a static pose, which is why motion is so helpful to see this stuff. However, if its just poor contraction, massage can help a lot. Proper training and better kinesthetic awareness (body sense) will go a long way to helping you. Especially since you said you were not very athletic prior to adulthood. It really could be just underdeveloped muscular patterns which is a training issue!
However, seeing someone who truly understands performance is the best bet. No knowing where you are regionaly, except for Alberta, here are two lists that I go to for practitioners in your area. Give me more specific location and I can tell you if I know a person in your area personally.
ART Practitioners - I know many in your region!
Trainers who can correct movement and neurological performance issues:
EDMONTON, AB T6A 0W8, Canada
Clairmont, AB T0H0W0, Canada
Get those videos so everyone can see these issues and how you go about correcting them!