Could someone tell me how the Stranger Things giveaways on Discord work?

Just for clarification and if they ever do something like this again:

the Bot would randomly post in 2 specific channels/threads a message about the giveaway and which cosmetic it includes. You had to ‚react‘ to that message and be the first to do it to win. you could react by just tapping/clicking on the message.

you pretty much had to click on the spot before the message popped up though otherwise you didn’t have a chance. People were using autoclickers or preclicking all the time. Hopefully if they ever do this again they don’t take the very first reaction but maybe make a random selection of the first maybe 10 or so people so that actually everybody has a chance, no matter the device or maybe even disabilities or something like that be in the way..