Sorry, but there's no secret code, no hidden meaning, no riddle to solve. The only purpose is to simply confuse the recipient - (and maybe entertain the sender too?)

a) Sorry, we can't tell you who sent it. 
(But it was likely  a friend - because they were willing to spend a few dollars to confuse you)

We suggest you simply ask everyone you know - or post on social media:  

#WTF - Who sent me this #ConfusingStuff from ConfusingStuff.com?!? 

And then...

You should definitely #PrankItForward and Send #ConfusingStuff to YOUR friends!

We didn't think it was necessary to explain; but then "Kevin from Jacksonville" accidentally sent Confusing Stuff to himself (and, yes, he was confused - but he was also mad at us!), so now we need to remind everyone...
At checkout, the "SHIPPING ADDRESS" is where we will SEND the Confusing Stuff.  
[Likely different than "Billing Address" which is YOUR address (or whatever address matches your credit card, Paypal, Amazon, whatever)]

•  1 MAILING --  There will be a ConfusingStuff.com reference card included with the confusing stuff. BUT, it will be initially hidden (wrapped, folded, contained in a smaller envelope, etc.) so the actual confusing stuff is seen before the ConfusingStuff.com card. Regardless, they still won't know it was sent by YOU - unless/until you tell them!
  
  
• 2 MAILINGS, approx. 2 or 3 days apart (exact spacing dependent on postal service) -- Only the SECOND mailing has the ConfusingStuff.com reference card - so, it's complete confusion after the first mailing, no mention of ConfusingStuff.com. (The return address will appear as a normal-looking address in Atlanta. They would need to Google the address to potentially find that it came from ConfusingStuff.com) Regardless, they still won't know it was sent by YOU - after either 1st or 2nd - unless/until you tell them!