>>105687124-- like look at that font one. first one shows on obvious realistic book, with a character that has construction lines around it. i can tell despite having not seen it before that this is something related to the display, storage or creation of fonts.
the second one looks vaguely like the first, but it may be difficult to tell that it's a book without remembering the first icon. basically it reminds you of the first icon, rather than what it's supposed to directly
the third one barely resembles the second icon. by itself i'd never know it was a book. the "a" lacks the construction lines of the first and font variants of the second, so it doesn't even bring "fonts" to mind. if you showed me that on its' own i'd assume it was just some program that use an "a" in it's logo or something