Here is a part of the moderncvstylecasual.sty
\renewcommand*{\maketitle}{%
  \makefooter{}%
  \newbox{\maketitlepicturebox}%
  \savebox{\maketitlepicturebox}{%
    \ifthenelse{\isundefined{\@photo}}%
      {}%
      {%
       \setlength\fboxrule{\@photoframewidth}%
       \ifdim\@photoframewidth=0pt%
         \setlength{\fboxsep}{0pt}\fi%
       {\color{color1}\framebox{\includegraphics[width=\@photowidth]{\@photo}}}}}%
  \usebox{\maketitlepicturebox}%
  \newlength{\maketitlepicturewidth}\settowidth{\maketitlepicturewidth}{\usebox{\maketitlepicturebox}}%
  \parbox[b]{\textwidth-\maketitlepicturewidth}{%
    \raggedleft\namefont{\color{color2!50}\@firstname} {\color{color2}\@familyname}}\\[-.35em]% alternate design: \MakeLowercase and no space
  {\color{color2!50}\rule{\textwidth}{.25ex}}%
  % optional title
  \ifthenelse{\equal{\@title}{}}{}{\\[1.25em]\raggedleft\titlestyle{\@title}}\\[2.5em]%
  % optional quote
  \ifthenelse{\isundefined{\@quote}}%
    {}%
    {{\centering\begin{minipage}{\quotewidth}\centering\quotestyle{\@quote}\end{minipage}\\[2.5em]}}%
  \par}% to avoid weird spacing bug at the first section if no blank line is left after \maketitle