Not sure if I should even call it a puzzle, but it does have somewhat puzzling quality to it. However it should be pretty obvious for you what to do, and if it is not obvious, then quite likely just need to skip this.

Granted, there are also people that will know what to do but are going to claim they can't do it. It's most likely they are just lazy / too easily discouraged / without proper approach to learning how to do this :P Because it really is easy just requires some practice and proper way to learn it. Just staring at the picture won't help you. Anyway if you're part of this group, you sadly need to skip this one as well, I'm afraid. Or finally learn :3

For the small percentage that cannot physically do this for absolutely legitimate reasons, what can I say, sorry?

The image

SOLUTION

Starting off with a comedic note curtesy of Krychek: the sailboat is a lie and hidden visions :D

Anyway... Actually the main thing to recognize on the picture was that the building block of the repating pattern is a QR code. There was no trick there but since the image came out bit blurry unfortunately some readers had some trouble reading it, I hear. Too bad :/ Cutting out just a single QR code was needed and possibly some cropping/resizing to make it bigger or something?

I used ZXing online decoder (don't actually have a smartphone myself). And it worked just with the cut out QR code without anything else on my part, that was first thing that my online search comes up with and something I use regularly if I need a QR code read. Figured that's good enough.

The message on QR code read:

Use your Magic Eye to view the 5 character giveaway code to put after http://www.steamgifts.com/giveaway/ - however, as an additional simple trick to make sure you've read this message, you first need to change the case (lower to upper and vice versa) and subtract 1 from the one digit that is present in the code.

Don't know what Magic Eye is? Well.. do a web search.. Anyway if someone knew that already, they probably did recognize autostereogram from the get go, but just viewing the image without decoding QR would leave you with an invalid code. Because you had to follow the instructions from QR to "fix" the code that was shown on the stereogram.

Some people physically can't see those indeed (especially due to vision impairment) but I think mostly it's just low will in trying to learn the trick properly :P

However, it is actually possible to analyse it programmatically or otherwise and there's even software possible to find online that does it. I understand this picture is an example of such analyser output. Some solvers actually manually tried to mess with the vertical strips imposing one on another to see if something comes up, knowing how autostereograms work, this is an example result.

So even if you actually can't view Magic Eye, the puzzle was solvable. Didn't exactly want to advertise such approach but the resourceful people managed to cope with that. What I wasn't really OK with was asking someone else to view these for you (running software written by someone else that you found on your own really is something different than going and asking someone for help).

Had this idea long ago based on random dot stereograms and the fact that QR codes do kind of come out as random dots. However instead of using single QR code and a copy with moved around pixels, I decided to create more modern autostereogram with a use of an online stereogram maker (there are more out there if you look around, this one is what I used).

Bit unfortunate I had to fight a bit with it to be satisfied with the output (it would resize the qr code I uploaded etc) but eventually settled down with what you saw. Pity it was still not good enough quality for some readers, but what can I say.

Congratulations solvers and especially the winner!