Using "img" is all the more surprising since the most common HTML elements such as "p", "h1/h2/...", "body", "dl", etc. were already defined and commonly used around 1986/87 in a vocabulary summarized in The SGML Handbook and detailed in ISO TR 9573 - Techniques for using SGML. Following that vocabulary/DTD, "fig" would've been more approriate, but then that old generic SGML vocabulary didn't know anything about URLs.