[NTG-context] Logo in the margin at the bottom of the page

Hello, I wish to place a small logo at the bottom of the page. It works almost but it is not very well adjusted. How to cure it ? Thank you. fabrice \showframe \useMPlibrary[dum] \setuplayout [height=middle, width=middle, backspace=2cm, topspace=10mm, bottomspace=10mm, header=10mm, footer=10mm, footerdistance=10mm, headerdistance=10mm] \setupfootertexts [margin] [] [{\externalfigure[dummy][width=\marginwidth,height=\footerheight]}] [] [{\externalfigure[dummy][width=\marginwidth,height=\footerheight]}] \starttext \dorecurse{10}{\page[dummy]} \stoptext