It was already discussed here that for layout purposes, where images and video appear on a web page, ordinary captions are probably best placed below the graphic — largely due to convention.
I want to take these considerations into navigation. Consider that you land on a category webpage, whose sole purpose it is to direct you to the appropriate sub-category by informing you what's inside each.
Without images — it'd look something like this:
Then, consider that each sub-category would probably be clearer if it had a relevant photo to make navigation easier. But where should it be placed?
The first task to tackle is deciding whether it'll be the images or the text that will be used as a primary cue for a user to determine where to navigate to. That may depend on the website. But even when that is done, for both considerations, should the image or text be displayed first? What does either imply? Or are the more or less equivalent?
Which would best illustrate that each block (image & text combo) forms a navigation link to the corresponding sub-category?