They're called "Labels" and you can add and manage them from the Home tab of Showcase!
Labels are added by this wee tag icon at the end of your showcases: Here it is, on the right.
Clicking this for any showcase gives you the opportunity to apply a label to that showcase.
Now, if you only have 1-3 showcases total, this tool is a little redundant. In smaller quantities, you probably don't need a way to sort and organise your showcases.
However, if you deal with multiple product lines, multiple regions, or multiple languages and you have a showcase for each - potentially with similar designs - then you may well need a smarter way of categorising.
Click the tag and it will bring up this screen:
Here you are able to name your tag and change the colour - you can beautify your labels girl!
Once a label has been applied, it show at the end of the row for that showcase, so you can see at a glance which labels have been applied.
At the top of the workshop Home, there are copies of the labels. Here's where the cool part comes in - you can click these copies to filter your whole showcase list by that label!
You can add multiple labels to each showcase.
On the app:
Viewers on the Showcase Workshop apps will also benefit from this new feature.
An example might look like this in the app context:
Viewer users can tap these labels to filter the published and labelled showcases so that they only see relevant showcases in that moment. Just like on the website, you can "un-filter" by tapping the labels again to deselect them.
Viewer users don't currently have the ability to add their own labels in the apps - it's still controlled by Admin users in the website.