If you want some spectacular art work of Mech's and the tech they work in and around, take a look at the "deviantART site. (its family clean even if the name may seem not.
This link is to "Battletech" related art work and some fantastic images, some using the designs from MWO, others from the original design's and some just newly created. http://www.deviantart.com/?qh=§ion=&global=1&q=battletech
[As a note there are some very details images and can be expanded at least 3 times, up to 4K image size.]
Here's a sample of the iconic "Warhammer" by Punakettu http://www.deviantart.com/art/Tropico-309917820
Check out other artists like; Shimmering-Sword, flyingdebris, and others.
And "Flyingdebris (Alex) is now the "Resident in House" artist for MWO. So we might not be seeing too much work from him as there are many "restrictions" related to Battletech related artwork and his contract with PGI. (MWO game developers)