There is no obligation to read descriptions before entering on the main giveaways page, so the winner is completely allowed to leave whatever feedback they see fit.
Play to win random prizes
https://feudalife.indiegala.com/
https://feudalife.indiegala.com/challenges
https://forums.indiegala.com/threads/feudalife-challenges-rules-updated-rules-coming-soon.1988/
or enter for a chance to win drawings among other users
https://www.indiegala.com/giveaways
You don't via the Giveaways page. It requires the gifter to enter a link to a Steam Store page, so users should have the reasonable assumption that all giveaways are for Steam keys.
I recommend joining a Discord group such as GrabFreeGames, as they have a channel called "keydrops" where users...
Every site that has some kind of wheel or slots does this, unless it's tightly regulated gambling like Vegas. The prize is predetermined before it even starts spinning, and the graphic is just there to feed excitement and for entertainment purposes only.
Alienware Arena Vault is about to give away a bunch of gog keys, so get ready to probably have to scroll through a bunch of giveaways if people dump them here :|
https://www.indiegala.com/giveaways/card/the-lost-ashford-ring/1160314
Legacy Games store key; not even noted in the giveaway description. The following ones do that at least.
https://www.indiegala.com/giveaways/card/the-lost-ashford-ring/1160383...
I shouldn't be forced to check every single giveaway description to see if it's for GOG. You have to enter a Steam Store page link when creating a giveaway, so users should have the reasonable assumption that they're getting a Steam key. If you don't like that then go start your own GOG...