Here is the SOOC JPG for the same image : http://s000.tinyupload.com/?file_id=88911356095628235668
Google Chrome might warn you of the risk for malware, but it seems to do for every good, free filehost :/
For reference, here is the screenshot : https://imgur.com/a/6RkiGyH
It doesn't do this for every photo either, which is even more baffling.
I hope you'll excuse the poor composition, but I didn't want to publish a photo I might put on an account with my name on it :)
Weird. I just did +1EV exposure and filmic rgb as is recommended, and it looks just fine to me.
What version of darktable are you using?
I think it might be a bug too. Which is too bad, because Darktable is soooo close to the perfect photo editor (except for CA correction and sharpening, but that's neither here nor there)