I just got a free reddit nft for being “a top Redditor”

I was scrolling reddit a few minutes ago and suddenly in my feed I see card that says "You've won a free reddit NFT!".

I click a button that says "claim" or something to that affect. Honestly felt like it was scam because seeing "you've won!" show up randomly raises some red flags. After clicking the button it shows me some of the reddit avatars with a button that says "claim yours"

Here's where I fucked up a little. Still feeling like it was some sort of scam or just plain not true, I click the claim button and suddenly I have the robot avatar, which was the first one to show up with the others. I could've scrolled and picked a different one I think but I thought clicking claim would give me a random one from the ones it was showing me.

I have some questions,

1) how many of you got one?

2) what exactly did I do to be considered a "top Redditor"? I scroll and upvote a lot but don't post often.

3) why isn't clearer that I'm picking out an avatar? Guess I'm not mad I got a free avatar that I didn't care much about before. But I wish I could've looked at the others and picked it out one I liked most.

Edit: shout out u/Maxx3141 for linking to an announcement post and for linking the collections on opensea

TL;DR: Reddit is giving out free NFTs to "top Redditors" who pass a karma threshold. What the threshold is and what other qualifications need met is not specified. You can claim it on mobile and if you are chosen, a special card will appear in your feed. This card in your feed is the only place to claim it. You can choose one of the four collections they have and you'll get a randomly generated NFT from the collection. You probably need your vault set up to get picked.

Wish I had chosen something other than the robots. I like the other three more but oh well. I goofed. Free stuff is cool.