Image CSS data type represents a two-dimensional image
https://developer.mozilla.org/en-US/docs/Web/CSS/image CSS reference declares
4 types of images, that can be handled: 1. Images with intrinsic dimensions
(a natural size) and thus fixed aspect ratio, that includes all raster
images. 2. Images with multiple intrinsic dimensions, existing in multiple
versions inside a single file, that includes ICON (*.ico) files. This may be
also TIFF, as they support multiple images inside one file, however TIFF
format is not supported in web. 3. Images with no intrinsic dimensions but
with an intrinsic aspect ratio between its width and height. This includes
all vector images, SVG first of all. 4. Images with neither intrinsic
dimensions, nor an intrinsic aspect ratio. This includes all gradients.