\documentclass[aspectratio=169]{beamer}
\usepackage[frenchb]{babel}

\usepackage{beamerx}

\title[Subtitle]{Title}
\author{John Smith}

\begin{document}
  \section{blah}
    \xsubsection{violet}[Short-title]{Title}{Subtitle}
    \xsubsection{violet}[Short-title]{Title}{Subtitle}[my-picture]
    \xsubsection{violet}[Short-title]{Title}{}
\end{document}