Odd Proof Sovereign (1887)

[SohoMint]

Another post from me AGAIN!
Early September I went to the RMM to study the tooling and coins of 1887. Obviously, there were some weird things - that is why I am studying such pieces (and slight influence by Andrew Thorburn, he knows he caused this). I cannot, for the life of me, get this Sovereign out of my head that I saw.

For context, the RMM had two proof sovereigns in gold (three if you want to count the reverse only uniface but not important). One sovereign had, the standard features you'd expect of a proof. Clear, shiny, reflective fields and muted matte design and legend. This was the same on both the obverse and the reverse - for those curious RMM 3785. The second piece, RMM 3786, had the same features on the obverse, mirror like fields, matte like portrait. The reverse caught me off guard though. The whole thing, shiny. Not just the fields, there was not a trace of matte-like features on the design or date! It was really uncanny, obviously not all proofs have matte-life features, but the fact that one side did and the other didn't felt weird to me. I don't know how else to describe it. It felt intentional, especially when compared to RMM 3785. You can find links to both coins at the bottom. Am I crazy? Is this normal? I will admit I am not the most experienced in proofs - but I will blame my lack of experience on my age (I'm only 18, I can only know so much!) It was such a striking distinction between the two pieces. Any insights, references or just comments would be GREATLY appreciated so I can get some proper sleep tonight instead of thinking about this damn coin! I've attached a photo, though not the greatest one - it is so hard to show what I'm talking about out of hand. 

https://royalmintmuseum.collectionsindex.com/object-rmm-3785
https://royalmintmuseum.collectionsindex.com/object-rmm-3786