Hey, @silentmoonss, yes: the bottom red arrow corresponds to the medial ridge of the scapula. As for the Acromion process, you got it close enough: it actually sits a tiny bit to the left of the upper red arrow. The Trapezius and the Deltoid muscles attach around the Acromion process, so we can use their volumes as clues to locate the Acromion. Notice that, because of the leaning (he's arching his back towards the camera) and the perspective (we're viewing the body slightly from above in this photo), the top planes of the forms of the Scapula are showing more, so we'll see the acromion more straight on. Envisioning the bones on photos of real people is often an exercise of imagination, and, to a certain extent, of memory and logic, too. If we can’t literally see the bone, we can sort of deduce it or guess it based on what we know about the human anatomy and by using other visual clues we see on the body. For example: we can’t always see every part of the Scapulas, but we always see where the spine is; so, from there, based on what we remember about the average proportions and the overall anatomy, we could sort of track a “route” to estimate where each part of the Scapulas would be. Other times, we can use the muscles we see and what we remember about their attachments to track where the bones should be located (as I did in this case). To develop this skill of envisioning the underlying bones, simply drawing the bones can help, but it’s also crucial to try to learn and remember a general sense of the anatomy, sort of like a “visual scheme” of the body in our minds. Hope you find this helpful! By the way, I took a quick look at your profile and I see you’re not currently taking Stan’s anatomy course. Have you taken it before already or are you considering to take it in the future?

as far as i can tell the scapula and the clavicle meet there. the traps end there and the deltoid wraps around... the muscle bello must be the infra spinatus... but i am not entirely sure...

@Steve Lenze @Jesper Axelsson