I feel like guild halls need some more attention again.
Though the green snipes are a cute, newer addition...

I'd like to see:
Tortodrone statues. Boss trophies come in sort of...3 stages. (For example: Jelly Gem, Crown, Jelly King). These smaller units that lack boss tokens could be 1-2 stages, with the first stage being just the shell or a non-corrupted torto. The second stage could be a life-size replica of the terrifying fiend torto, glowing purple bits and all.
These would of course take glyphs and ancient shells, as well as other related materials, to craft. I know that shells can be a task to get, but myself and many friends already have enough for all the new shields, so this could be something else fun to do for people who love SK too much.

Let's further impress Armero with the Hunt!

In addition to statues:
Those purple vortex blocks are amazing. They are very fun to play with. Having one in the hall to detonate and interact with would be awesome.

Some other small furniture, like moss covered rocks, ferns, waterfalls (I LOVE those waterfalls in the March of the Tortodrones mission "lobby"). To make the hall seem ancient and...serene. Perhaps even the new fiend sigils (the ones with a pit boss in the center and lower fiend ranks around it, that portals appear on) could be placed around as a sort of carpet. Oh! and piles of dark matter deposits.

Yay! Moar aesthetic things! Aesthetic. Yes. Shiny...

Edit: on a side note, an "authentic tortodrone mask" (non-expiring) would be awesome, especially if it matched either the ancient plate, serene, or power pistons/aggro aura. Both a normal and a corrupted mask plx!

Aesthetics are too easy to come up with :P.