I don't think there's anything resembling a shallow DOF with the X100... It requires quite a distance between subject and background *and* wide open. I've been trying for months.
Don't forget the basic principles of photography, and in simple terms, the closer you are to your subject the greater the blur/OOF will be behind the subject when shot at a wider aperture and with seperation between subject / background and consequently, the narrower the DOF will be.
The first image clearly demonstartes this principle as the subject matter is close to the camera (H&S on 35mm equivalent lens requires close camera to subject distance), if the photographer used a wide aperture f2/2.8, then the DOF behind the subject is dramatically reduced and the effect of blur/oof increased.
This is another reason why macro photography requires a smaller aperture to ensure sharp focus/good DOF across the subject matter to counter the lens to subject distance
For a more in depth explanation read this or search Depth of Field.