Alpha to Logo filters work with the alpha channel of the active layer to add different special effects. Keep in mind that you always need an alpha channel to work with these filters.
Any Alpha to Logo filter can be added by following these steps:
Open any existing image.
If you want to apply the effect to an area of it, use the Selection Tool (Optional).
Choose any of the Alpha to Logo filters, modify parameters, and apply.
The Alien Glow adds a spooky glow around the layer's alpha channel. If you apply it to a full layer maybe it doesn't add much to the image, but see what it does after a little layer duplication and reordering.
Right-click on the layer's name inside the layers widget, and select Add Alpha Channel. Duplicate the layer, and create your selection. Then, apply the filter.
I know, it doesn't look like much yet, but after a little layer reordering, you'll end up with a cool effect:
Place your duplicated selection layer on top and your original...