I did miss them but managed to understand which way was each anyway. My biggest problems weren't in understanding which element went were, but were 1) in understanding that the book should have been used on the table and 2) in which alcove to put which spell of the same element (which is quite a number of combinations).Many people missed the elemental glyphs above the alcove rooms, and therefore found it confussing where to place the scrolls
Of course, my 2 cents on that room , plus probably I just missed some hint just like I missed those glyphs.