Nintendo has added a minor update to Miiverse for Wii U this week, to match the 3DS version.
The upgrade tweaks the user interface to enable quicker access to certain aspects of the service whilst reading. According to Nintendo's Miiverse buff Marty, the changes affect just Wii U access, "bringing it in line with the Nintendo 3DS version."
1) The button for reloading is no longer the L Button. From now on, use the Y Button to reload the current page.2) We've added a new feature. When a community is open, you can use the L/R Buttons to quickly move up and down between posts.
Are you using Miiverse on Wii U, 3DS or both systems?