I have the same observation on my worksheets. So what I do is after I
evaluate everything I export that to a HTML so I have all images and the
symbolics, numerics as well.
Unfortunately the editable worksheet will always just give you the links
the image path and filename and thats it. So in a way we could say that it
does not really "embeds" the image. This maybe a known limitation we
probably need to accept.
Its easily done in MathCAD and is truly embedded but thats commercial stuff.
Regards,
Berns B.