\starttext

\startbuffer[samples]
@IMAGE {sample1,
    title       = "sample-1",
    author      = "My Self",
    mpcode      = {fill fullcircle scaled 4cm withcolor "darkblue";}
}

@IMAGE {sample2,
    title       = "sample-2",
    author      = "My Self",
    mpfile      = "metafun-001-sample-2.tex"
}
\stopbuffer

\definebtxdataset
  [samples]

\usebtxdataset
  [samples]
  [samples.buffer]

\definebtx
  [samples]
  [default=,
   specification=samples]

\definebtx
  [samples:list:image]
  [samples:list]

\definebtxrendering
  [samples]
  [specification=samples,
   group=samples,
   dataset=samples,
   method=dataset,
   numbering=no,
   criterium=all]

\startsetups btx:samples:list:image
  \tbox \bgroup
    \bTABLE[offset=1ex]
      \bTR
        \bTD[ny=4]
          \dontleavehmode
          \doifelsesomething{\btxflush{mpfile}} {
            \externalfigure[\btxflush{mpfile}]
          } {
            \MPcode{
                \btxflush{mpcode}
            }
          }
        \eTD
        \bTD
            \btxflush{title}
        \eTD
      \eTR
    \eTABLE
  \egroup
\stopsetups

\placebtxrendering[samples][criterium=all]

\stoptext