Interesting, though probably much-known fact, is that in the Middle Ages only members of the Church and the rich could read so pubs used these illustrative signs so that people could find them, especially travellers looking for a bed for the night....
The Eagle & The Child, by the way, is a real pub. My wife and I shared many a bitter in there, in the back corner where JRR Tolkien, CS Lewis and others used to hold their "Inklings" meetings. For a nerd like me, it was nirvana. Also, the bitter was good. If you're ever in Oxford...do swing by The Eagle & The Child (or The Bird & The Baby, as it's also known).
Related note: I love how the English always have nineteen names for their local pub. When I lived in Canterbury, I swear my local had 500 different nicknames. You never knew what people were referring to when they asked you to meet up for a pint. :)

