There is no easy way for this built in Mendix. I would build a solution myself by placing a thumbnail of the image in a container underneath the link that I only show when someone hovers over the link. Look at the following CSS tutorial on how to make tooltips using CSS: https://www.w3schools.com/css/css_tooltip.asp, and some documentation on how to implement CSS styling in Mendix: https://docs.mendix.com/howto/front-end/customize-styling-new.
Our SL – Popover widget also works perfectly to show dynamic content, like images. Popover trigger can be any other widget.