It is possible that the composer of this picture, happy to be anonymous, believed himself to be rendering an accurate portrayal of the nature of man. We cannot speak of symbols in a world suffused with distinctions which unify. Let me point to the levels of man I propose this picture is meant to convey.
The dog, is the body of a man. Tough, effective in procuring the realities of food, and shelter.
The rabbit, in the saddle directing things, is man's emotional nature. Particularly astute since some see this layer as the source of the idea of sin.
And the preyer, a riff on the falcon, is the snail: the snail then is man's intellect. In its time, everyone got the joke, uneducated and clerical bigwigs alike. And they laughed, because they were comfortable in their own skins. And imbued with a vision of unity.
And this might be a good reading.
(Here's the citation, something I rarely have to use, as a matter of principle.)
