\documentclass{bidipresentation}
\usepackage{graphicx}
\usepackage{xepersian}
\begin{document}
\begin{rawslide}
  \newcounter{reversestepno}%
  \newcommand{\backstep}{\step(\setcounter{reversestepno}{\value{totalsteps}-\value{stepcommand}+1}\ifthenelse{\value{step}=\value{reversestepno}})}%
  %
  % We use the custom command \parstepwise which not only wraps the whole argument of \stepwise into a minipage (because
  % otherwise vertical spacing goes haywire, don't ask me why), but also gives substance to steps.
  %
  % If the following \stepwise command would only contain the calls to \backstep, everything would be fine.
  % But we _had_ to add something else....
  % In the second part of this application of \stepwise, several steps are executed simultaneously with those executed
  % backwards in the first part. This means the value of the counter totalsteps is 14, i.e. the calls to \backstep
  % correspond to steps 8...14. To remedy this, we decree that the first step performed shall be number 7, by setting
  % the counter firststep accordingly in the optional argument of \stepwise.
  %
  \parstepwise[\setcounter{firststep}{\value{totalsteps}/2+\value{firststep}}]
  {%
    \begin{quote}
      \Huge
      \backstep{آیا} \backstep{الان} \backstep{می‌توان}
      \backstep{متن را} \backstep{در جهت} \backstep{برعکس}
      \backstep{نوشت\,!}

      \bigskip

      % By determining explicitly the times at which the following steps are executed, we make them appear
      % simultaneously with the preceding flock of \backsteps. As we have set the counter firststep to 7, we start
      % counting with 8.
      %
      \step[\value{step}=8]{\includegraphics[width=2cm]{fig-1}}
      \step[\value{step}=9]{\includegraphics[width=2cm]{fig-1}}
      \step[\value{step}=10]{\includegraphics[width=2cm]{fig-1}}
      \step[\value{step}=11]{\includegraphics[width=2cm]{fig-1}}
      \step[\value{step}=12]{\includegraphics[width=2cm]{fig-1}}
      \step[\value{step}=13]{\includegraphics[width=2cm]{fig-1}}
      \step[\value{step}=14]{\includegraphics[width=2cm]{fig-1}}%
    \end{quote}
    }%
\end{rawslide}
\end{document}