Should "Add Items" bounce instead of the page list in Menus?

When you click the DM icon to get to menus, the menu itself shakes. Should we shake the "Add Item" button instead? Or should we assume people's primary action is editing the menu as a whole, not adding a new menu item?

Start by reproducing the behavior reached through the DM icon in Menus and observe whether the menu list or the "Add Item" button receives the shake. The issue does not name files or tests. Work is not complete until the interaction choice is agreed and the resulting behavior is implemented.

Written by the indexing model from the issue text.