Mixed images and text menu

Hallo!

Following question – I build a site with menu where parent items are images but their children are text. CSS is formated to show/hide submenu items on rollover on parent menu items.
The problem is, how should I use wp_list_pages() function to make it work?
Please take a look at my page:
https://pavisam.derigs.lv/mengis

Above are menu built with wp_list_pages(‘title_li=&depth=2’) function, bellow – the expected result.

Thanks in advance!