Given this UI (in HTML), do I need to put texts beneath the large images, or is the small image displayed in the lists enough to make the connection?
The client has signed off on the design above. They feel that the tool-tips combined with a BG on mouseover of the big image, with the BG color repeated for the menu and body links, is enough to make the connection. The colors of the small images have been made more obvious by not giving the image a black line border (doi!). In the screenshot, the mouse is hovering over the image for The Quran - though I missed capturing the tooltip.
The client is happy with the images themselves. (Which now have pretty gradients.)
Thanks to all for the tips!