Hey! I noticed something about the characters' infobox on Welcome To Japan, Ms. Elf! Wiki, and I hope you don't mind me pointing it out. :)
The infoboxes use tabber for image in a data tag instead of image tag, in order to accommodate the nested tabs. However, while nesting tabs with image wasn't possible for a long time, this flexibility has been possible thanks to panels since quite a while. I'd recommend using that way, as that's a portable-friendly and preferable method.