[pdftex] Why does pdflatex needs pictures?

[Lars Madsen]

On 2011-01-16 18:10, HHa wrote:
> Hi David, and others,
> I found another solution:
>
> \usepackage{graphicx}
> \let\oldincludegraphics\includegraphics
> \renewcommand\includegraphics[2][]{%
>     \IfFileExists{#2}{\oldincludegraphics[#1]{#2}}{\fbox{Bild nicht da!}}}
>

I still do not understnad the need whem the demo option should work just 
fine