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

\usepackage{beamerx}

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

\begin{document}
  \begin{xpic}[h]{my-high-picture}
    \bf\color{white}Text
  \end{xpic}
  \begin{xpic}[w]{my-high-picture}
    \bf\color{white}Text
  \end{xpic}
  \begin{xpic}{my-high-picture}
    \bf\color{white}Text
  \end{xpic}
  \begin{xpic}[h]{my-wide-picture}
    \bf\color{white}Text
  \end{xpic}
  \begin{xpic}[w]{my-wide-picture}
    \bf\color{black}Text
  \end{xpic}
  \begin{xpic}{my-wide-picture}
    \bf\color{black}Text
  \end{xpic}
\end{document}
