An image in itself has no executable instructions inside. It's a piece of information, a set of bits and bytes that are usually compressed. Decompressed, it results in a bitmap. That bitmap can then be translated through any image processor into the colored pixels one sees on a display.
A vector image is different from a raster image, in the sense that the format itself defines some instructions, that are later calculated by the software. An example of it is SVG (Scalable Vector Graphics).
However, there is no single consensus on how to present images. For instance, you can use either the GPU or the CPU in order to process the information (which will entail different assembly instructions), there exists a countless number of languages, and any one might produce different assembly instructions, although they do the same visually.