\copyrightVincent

\begin{saveblock}{code}
    \begin{highlightblock}[linewidth=0.9\textwidth,gobble=8]
        $ \displaystyle\sqrt{\phantom{\frac{2}{3}}} $

        $ \displaystyle\sqrt{\frac{2}{3}} $
    \end{highlightblock}
\end{saveblock}

\addtorecentlist{\textbackslash phantom}

\begin{frame}
    \frametitle{Phantom}

    \begin{columns}
        \begin{column}{0.9\textwidth}
            \useblock{code}
        \end{column}
        \begin{column}{0.1\textwidth}
            $ \displaystyle\sqrt{\phantom{\frac{2}{3}}} $

            $ \displaystyle\sqrt{\frac{2}{3}} $
        \end{column}
    \end{columns}
\end{frame}