Ribbon cable question
One example why we use something similar:

We have a display which we use to connect to our board. The display comes with a flex foil. We also have a second source for this display from a second vendor. To identify the display vendor type we ask second vendor to short two traces. The flex foil as such is supplied by third party to both LCD vendors without bridging.

The board can easily identify the type of the display connected and load appropriate settings for the display.