How crooked is Leon County?

Today is the start of early voting in Leon County, Florida.  My wife asked me to mail her absentee ballot on the same day.  I planned to vote early, so as I readied for my trip to the post office, I brought my absentee ballot with me to turn it in. 

I tossed both envelopes into the car seat and noticed something unusual.  My wife is a registered Democrat, and her envelope was postage-paid with "par avion," which is French for air mail.  I'm a registered Republican, and my envelope had clear bold-type letters stating that postage needed to be applied.  (See the photo below.)

Hmmmm.  Why the difference?  Is it a mistake?  Is a random error where some received a free postage-paid envelope, while others didn't?  Was it intentional?  Did only Democrats receive the postage-paid envelopes, and Republican didn't?  Did the Florida DNC or the National DNC pay for this service?  Are there other services these organizations paid for?  If so, what are they?   My wife's envelope is signed, while mine is not.  Things that make you go hmmmm.