Unusual Automated Postal Center Label

Why does this label have instructions to fold it in half, with a similar-sized bit of sticky label that would be folded back?

I'm not sure I have an answer, but would just share this observation:

Could it be that perhaps it was intended that the "fold here" line would be placed to the far right side of the envelope and folded over onto the reverse side?

I suspect that the location of the "stamp/label" on the envelope would have to be positioned in a way to be read by automated mailing equipment. If the "stamp/label" were placed too far to the left to allow that blank space to be on the face of the envelope, it would probably be "kicked out of the system" and would have to be read manually to verify proper postage.

Wow, very insightful. Thanks!