Your icon is your avatar in the Discord. However, in terms of interacting with the channel, there are some things to keep in mind.
Appearance to the bots Edit
Whoever you faceclaim with your icon will be set as your digital avatar and appearance with the bots so long as it is a registered character (video game and anime characters, generally). So things such as height, weight, assets, and base strength would be determined by who you faceclaim. If one does not want to faceclaim a character, they could draw their own icon and it would be set as their appearance.
Nonhumanoid icons or unregistered characters will be rendered as a Greyface. The bots would see you as a vaguely human-shaped grey figure that they would still be able to register as you.
If one is a regular long enough and consistently keeps a faceclaim, their digital avatar will be locked to that character's appearance regardless of actual icon. While this is necessary for certain activities in the channel, it is not required. Mods are locked as their blog faceclaim by default. If one is a consistent regular, who keeps changing faceclaims, and is deeply involved with channel activities, they may get their icon locked to one character by Oumod.
This is, thus far, restricted to mods and a select few regulars. They are able to change their outfits according to their current icon. Even fewer have registered wardrobes that do not correlate to their icon but are able to wear.