The problem appeared in the system with an Office 2013 installed.
Ppt with smartart.ppt is an original ppt file.
Ppt with smartart.pptx is result saved by PowerPoint 2013
~dwcskfsw.xe2tmp.pptx is a result of conversion from ppt to pptx which was done using
Office 2013 automation.
Power Point 2013 or 2007 can open and show SmartArt from either ~dwcskfsw.xe2tmp.pptx or smartart.pptx with no problem
The difference in those pptx are in drawing1.xml :
in ~dwcskfsw.xe2tmp\ppt\diagrams\drawing1.xml has no information
in smartart\Ppt with smartart\ppt\diagrams\drawing1.xml has smartArt information.
(Diagrams folder contains smartArt data).
as result Aspose can not read properly smartArt data from ~dwcskfsw.xe2tmp
and conversion by Aspose.Slide from ~dwcskfsw.xe2tmp to jpeg which we use showing no smartart
stuff at all.