They could still be shown just under corresponding code in between lines, alghough there would be a lot of space around them. But showing them after the line is also an option, maybe along the right edge of the pane, wrapping long lines earlier before them.
When caret is in the code, then highlight frame (border) around corresponding image. And when cursor hovers over image then highlight corresponding code.
Related:
Request for showing transclusions in the same way will likely follow. Editable transcluded block between lines of main file could look like this: https://en.wikipedia.org/wiki/Brackets_(text_editor)#/media/File:Brackets_live_preview.gif (see the line numbers). Images would be laid out similarly, just would not be editable (unless there is image editor plugin, e.g. for svg images).
#/media/File:Brackets_live_preview.gif){kind=link}