diff --git a/prepends/figure.typ b/prepends/figure.typ
index c053398..73ec4c8 100644
--- a/prepends/figure.typ
+++ b/prepends/figure.typ
@@ -1,3 +1,7 @@
+// Given a figure with an image, this show rule will wrap the image in a link
+// that goes to the full version of the pic.  For example, image("bird.jpg")
+// will get wrapped in a #link("bird_full.jpg").  This, of course, assumes
+// bird_full.jpg also exists in the directory.
 #show figure: it => {
   if it.body.func() == image {
     let src = it.body.source