To also show the section auto-generated number as in "Section X.Y My title" we add the optional {full} boolean argument to the cross reference, for example:
which renders as:
{full} is not needed for cross references to most macros besides headers, which use full by default as seen by the default_x_style_full macro property in --help-macros. This is for example the case for images. You can force this to be disabled with {full=0}:
Compare \x[image-my-test-image]{full=0} vs \x[image-my-test-image]{full=1}.
which renders as: