In graphic design, including UI/UX, there's a lot of visual shorthand to tell users what's going on without explaining it through text. It's not entirely standard across the web but there's a silent agreement to do things roughly the same for ease of use reasons (and if you've ever taken a beginners graphic design class you'll know what I'm talking about). You want someone to be able to open your app and go "Ah yes, this triangle button means play" or "This red color means something went wrong".
For reactions, the emoji is now outlined in bright purple to signify you added it. But this is the same design language that tells you when something is actively selected and ends up making it feel like I'm supposed to be looking at that one thing on the screen even though it's unimportant.
You can see the same usage of a colored outline to signify focus even on Discord's feedback form; click in the title field and ope, purple outline. Firefox, URL bar gets outlined in your accent color. Windows start menu, search bar outlined in accent color. It's visual shorthand that tells users "hey, this thing is what you're currently interacting with" that is being wrongly applied to something that isn't in focus.
A more muted or less bold signal would be better (such as the old color shift approach). A non-colored outline, a lighter background, that sort of thing.