See Pop-Up Text in Microsoft Word and my free Add-In Pop-Up Text Add-In for Microsoft Word. I do not know that this will add an image, though.
It works, as far as I know, with any text, not just citations, in Word.

To have it take you to another spot with a click rather than simply display the text, use a hyperlink field. The pop-up text is whatever you put for the screentip when creating the hyperlink. This is discussed in my article on pop-up text and in:

• Add Screen Tips to Text in Word by Lene Fredborg, MVP
• Hyperlink field

Both my article and Lene Fredborg's focus on the popup text aspect of the fields.

To get pop-up text, you could also use a footnote or endnote instead of a citation. This produces pop-up text (the full text of the footnote/endnote) when the mouse pointer hovers over the reference number in the text. If the note in the text is clicked on, the user is taken to the note, which could contain a hyperlink.