Firstly, thanks for such an in-depth comment! Secondly, the white space was actually me being incredibly lazy, but we'll just pretend I did that on purpose, 'kay? xD Thirdly, Harry's pose is something I'm so very pleased turned out like I envisioned it - for me, it's saying, "I want to touch you but I can't so I'll just hold myself away so I don't get reminded of this... again. ...I miss you..." As for Severus, my thought was that he hadn't even noticed Harry standing there for one reason or another - but it could well be he did and he's not looking on purpose. You never know with him! (And I won't know until I write the fic. xD)
It is not your imagination! There is, indeed, a pin/brooch that matches Harry's locket in the center of his cravat. And that is very much the clue, since I didn't think Severus would wear a locket, but he might just wear a pin/brooch. Especially with his formal and very old fashioned dress robes! So have some cookies! *offers a plateful* :D
Once again, thank you. I'm so glad you liked this!