N.B. The above image has been scaled down to 75 percent of the original size.
The above come from PNGs which have graded transparency. Here I have displayed them on the Compo canvas with a deliberately glaring background colour and exported as GIFs with no mask to show up the transluscency in browsers that can't display PNGs correctly.
Above reduced to 75 percent size.
Above is a GIF so, although dithered, lacks the colour depth of the PNG original.