The problem with this nice aluminum bezel is really the ugly black rubber band surrounding it, and the black hinge (just look at theclosed laptop : the only distracting, black accent is the hinge). A seamless grey look would look gorgeous even with the black keyboard, just look at the MacBook Air !
I think the black keys are a very sound idea to avoid the keys wearing off with use, and revealing the ugly colored plastic they're made of.
About the black bezel looking better : nothing prevents you from having a shiny plastic sheet cut to the right size, and sticking it over the alu bezel. Provided it's thin enough, it would work.
I currently have the glossy MBP and except in my dark bedroom, it's a nightmare to use in bright places. At first I wanted to get a custom-cut alu bezel, so I could remove the glass and hide the innards (probably voiding my warranty in the process, which is why I backed off).
Something like this :
https://forums.macrumors.com/posts/8156316/
But if you want a black bezel so hard, you could just opt for a black anodized alu bezel instead of the bare metal one... and being matte, it would compliment the matte screen nicely. Metal cutting companies often offer a choice of materials, and anodized black is one of them.
Perspective was used by artists since the 15th century. Have you ever been to school ? you're seeing the effects of a wide angle lens that makes objects appear "stretched" near the edges, as opposed to a telephoto lens that compresses perspective and would have given you a rectangular trackpad.
Knowledge is power, ignorance is bliss. I'm sure the poster had nothing better to do than fake an in-store pic