I've got to say that I am really disappointed by the concept art on The Elder Scrolls On-line.

Sure it looks pretty but it nothing how I imagined a representation of Tamriel. I hope it doesn't hold back future TES games.

I think what let TESO down in my opinion was it all looks mostly like Europe and doesn't have the diversity of climate and culture which I've come to expect from TES. I've seen modders on YouTube make better worlds like the new moonpath to Elsweyr.
I was expecting to see dense jungle rainforests of Valenwood & Elsweyr. Elweyr turning into desert land style canyons and hills looking something like area at the famous Khyber Pass of Afghanistan.
Black Marsh I was expecting to see like the marshy swamps and peat bogs of Indonesia cross with cities like the ancient Angkor with Hist trees growing up through the stonework.
High Rock I expect to be the woodland region with high mountain peaks and little villages like Stone Age Britain & France for the common folk or cities like Camalot for the ruling class and nobility.
Elven folk I expected to look very eastern Asiatic or ancient Americas inspired in arcitecture only extremely exaggerated to be almost alien looking like crystal pyramids with elaborate features. Like how artists often depict the city of Atlantis to have been. Hamnerfell very Sahara as it is. Like the Tatooine of Tamriel.

What I thought was it all looked very Europe
Inspired with The exceptions being Hammerfell Black Marsh. When I saw the picture of Black Marsh I actually thought it was Valenwood and it was one of the tree cities until I zoomed in. Black Marsh could have been so much more and more cultural in arcitecture. i thought it was Bosmer who have giant trees. Wheres the diversity? Argonians I expected to have ancient cities that stretch underwater and have roots and vines growing all weaved throughout them. Skyrim looked great with the long houses pitched up on cliff edges. The little town with crooked European style houses I'd expect to see as a man village and not Elven.

Hopefully future TES games won't be so restricted. What happened to the imagination and feeling we had in Morrowind? With that very Asiatic Turkic feel to the Dunmer but also so very alien at the same time. Far from European influence we expect of man empires. It was good as it gives a world of diversity of cultures and terrain.

I've seen people saying the TESO is treated like a seperate game so hopefully future TES provinces will look much better and will offer so much more culture and diversity