RemixIconEx.Device.device

You're seeing just the function device, go back to RemixIconEx.Device module for more information.
Link to this function

device(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.Device.device()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M19 8h2a1 1 0 0 1 1 1v12a1 1 0 0 1-1 1h-8a1 1 0 0 1-1-1v-1H4a1 1 0 0 1-1-1V3a1 1 0 0 1 1-1h14a1 1 0 0 1 1 1v5zm-2 0V4H5v14h7V9a1 1 0 0 1 1-1h4zm-3 2v10h6V10h-6z" />
</svg>

example usage

svg.icon {
  width: 96;
  height: 96;
}