Are you referring to the avatars in your above screenshot? I do not see any emojis, only the frog gif.
Sometimes dark mode effects avatars, displaying the inverse of what is shown...i have experienced that on the forum while using dark reader plugin for Firefox. Other than changing your avatar to something other than a light color, you would have to disable dark mode and manually modify, if possible, each part/application you want dark. I'm no expert on this, and you would have to talk with the devs of an application to find out for certain, but some of these modifications may only be possible within the source code.