Often, when one dreams of working in a den or small space, they are pursuing their interests as well. It is a signal that they need more efficient spaces in order to focus on what they desire and avoid wasting time on too many other things.
Lets work smarter. Lets not get knocked-off our track by distractions. Should you ever find yourself working in a small, den like space, chances are doing so is an indication that you are taking time for concentration and efficiency. Work in this particular environment might indicate that you are spending less time on leisure or with family. This situation might have led to your productivity level increasing significantly.