Here's the text from the video.
Today I learned a neat little trick that works in both Discord and Slack.
Say for example you want to add some emoji reactions to someone's post. Normally when you do that, if you need a different reaction you would click here then add a heart and then if you want another one you gotta click here and add another thing and it's kind of a pain in the rib.
Well you can actually hold down the shift key and you can click all the ones you like And it will stay up without you having to open it over and over and over again. And then, when you're done, you can just click the last one and it goes away. So it's a really fast way to add a lot of reactions in Slack and in Discord.
