Let me explain.
Tilt shift doesn't make the image look blurry, tiltshift IS making the image look blurry. (In a fake tilt shift anyway. A real tilt shift lens focuses on subjects, etc... too long to explain.)
When you focus on something close to you, everything farther away (and closer) is out of focus. So when you blur the background of a rather large building it looks like it's close, making it look small.