Admittedly, I only looked at the photo. But according to the creator,

"With two donor bikes and some other junk, any tinkerer can build a front-wheel-drive, center-steer, semi-recumbent bicycle. (FWD/CS/SR bike for short.) No welding or brazing required! No special tools required! No power tools required (but they can help)."
He also says it's very comfortable.

There must be duct tape involved.