That's exactly my point; the "Use the code" arrow only points to 'SWEETTHANKS' — it's the only valid code on those two.
It wouldn't be the first giveaway in history when multiple codes are hidden in the picture despite expectations. Having a broken code on the picture is just shitty marketing, especially since it shows up as valid and never expires. It just promotes how buggy and slapped together GOG's infrastructure is through and through. But we should get back on topic.
What will this code unravel?
We'll give you a hint - something really cool
"this" not "these"
"code" not "codes"
Also the 'SWEETTHANKS' part of the image is edited; they just picked an image and slapped the code there.
Btw, I dislike how they went about this too, as it causes confusion.
And yeah, we're off topic — so last one from me.