Regardless of your lack of wanting to gain too much additional mass, your triceps definitely don’t overpower your delts, that part is still true. So if all your goals entail is another 10-15lbs of LBM, there should still be triceps work included in there. If anything you may want to cut down on anterior delt work for more rear work, that’s that bigger imbalance I see, your anterior delts actually look quite good for someone your size.
You are very lean. Add mass. There is nothing overpowering about your upper arm.
I seriously recommend reading Meadow’s article on shoulder training
If I had to pick one shoulder exercise to do for the rest of my life, it’d be heavy ass side laterals…Changed my delts tremendously.