RemixIconEx.Media.picture_in_picture

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

picture_in_picture(icon_css_class \\ "icon")

iex> Elixir.RemixIconEx.Media.picture_in_picture()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="icon">
  <path d="M21 3a1 1 0 0 1 1 1v7h-2V5H4v14h6v2H3a1 1 0 0 1-1-1V4a1 1 0 0 1 1-1h18zm0 10a1 1 0 0 1 1 1v6a1 1 0 0 1-1 1h-8a1 1 0 0 1-1-1v-6a1 1 0 0 1 1-1h8zm-1 2h-6v4h6v-4z" />
</svg>

example usage

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