The change() method calls the internal update method, as seen in the tag's module source code. Whenever a bound attrib changes, the tag's change() methods executes. Using the subscribed attribute, you can push those change events to other veneer tags.
the veneer-timer tag sports a change() method, just like all other veneer tags.
Change the <veneer-timer>'s attributes using a <veneer-attrib> tag, and notice the change event firing: