This is a solution
\documentclass{article}
\usepackage{afterpage,everypage}
\usepackage{mwe,lipsum}
\AddEverypageHook{%
\ifodd\value{page}\else\afterpage{\includegraphics{example-image-a}\vspace{\textheight}}\fi}
\afterpage{\includegraphics{example-image-a}} % why this is necessary?
\begin{document}
\lipsum
\lipsum
\lipsum
\lipsum
\lipsum
\end{document}
Edit: warning this is not good if you have figures, tables or footnotes
\documentclass{article}
\usepackage{afterpage,everypage}
\usepackage{mwe,lipsum}
\AddEverypageHook{%
\ifodd\value{page}\else\afterpage{\includegraphics{example-image-a}\vspace{2cm}}\fi}
\afterpage{\includegraphics{example-image-a}} % why this is necessary?
\begin{document}
test
\begin{figure}[t]
some test
\caption{some}
\end{figure}
\begin{figure}[t]
some test
\caption{some}
\end{figure}
\begin{figure}[t]
some test
\caption{some}
\end{figure}
\lipsum
\lipsum
\lipsum
\lipsum
\lipsum
\end{document}
footnote
\documentclass{article}
\usepackage{afterpage,everypage}
\usepackage{mwe,lipsum}
\AddEverypageHook{%
\ifodd\value{page}\else\afterpage{\includegraphics{example-image-a}\vspace{2cm}}\fi}
\afterpage{\includegraphics{example-image-a}} % why this is necessary?
\begin{document}
test\footnote{\lipsum\lipsum}
\lipsum
\lipsum
\lipsum
\lipsum
\lipsum
\end{document}