The engines look amazing.
However, that center whitish building does not look nearly as good; not only does it look much "cleaner" than the usual more rusty and industrial style of Factorio, but even the art style looks different, being flatter and more "line-art". It looks like something from a cartoon.
Fortunately, this looks to be a one-off (and might in fact be a case of that building still being WIP); the grinder and arm-socket buildings look fine.
I only call attention to it because I have been doing a lot of Subnautica recently, and the style clash between their old and new audio designers is...drastic to the point of being jarring and affecting the experience, and I had an initial moment of fear that something similar was going to happen here.
Hi, indeed the structure in the middle is just a 2D drawn placeholder, and the real finished version is being created based on it.