[css-fonts-4] font-variation-settings animation doesn't work like transform

#1580

Author: litherum

css-fonts-4/Overview.bs

@@ -2619,9 +2619,8 @@ variations defined for other font formats
 should attempt to follow the pattern of registered variation axes.
 
 Animating font-variation-settings is possible
-using a mechanism similar to animating the 'transform' property:
-Two declarations of font-feature-settings can be animated between if they are "like".
-"Like" declarations are ones where the same set of properties appear (in any order).
+using the following mechanism. Two declarations of font-feature-settings can be animated between if they are "like".
+"Like" declarations are ones where the same set of properties appear (in any order). Because succesive duplicate properties are applied instead of prior duplicate properties, two declarations can be "like" even if they have differing number of properties.
 If two declarations are "like"
 then animation occurs pairwise between corresponding values in the declarations.
 Otherwise, animation is not possible.