\documentclass{beamer}
\usetheme{default}
\begin{document}

\begin{frame}{Outline of the talk}

\begin{itemize}
  \item Introduction
  \pause
\includegraphics[width=.5\textwidth]{horsecock.png}
  \item Statement of the main theorem
  \pause
  \item Technical lemmata
  \pause
  \item Proof of the main theorem
  \pause
  \item Conclusions
\end{itemize}

\end{frame}

\end{document}