The HTML output from ArtOfTest.Runner.exe from failed test is missing the expected and actual image on failure. The same details are available, if the output is generated from Test Studio Standalone version.
The actual image on failure exists in the specified output location, but is not included in the HTML. When you open the results with the Result Viewer, you can see the actual image on failure, but the expected image is still missing. Maybe those are 2 separate things to look at.