@Johannes_B Well, I wrote this: now \begin{wrapfigure}{r}{0.5\textwidth}
\vspace{-20pt}
\begin{center}
\includegraphics[width=0.48\textwidth]{metrofisso1.jpg}
\includegraphics[width=0.48\textwidth]{metrofisso3.jpg}
\end{center}
\vspace{-20pt}
\caption{A gull}
\vspace{-10pt}
\end{wrapfigure}