The Synchronize toolgroup contains tools for turning on synchronised viewing and some grid management tools.

Turning on the Sync icon when you have 2 or more cells open in your grid will trigger synchronised viewing, you can see a quick video of this below:

The other functions are:

1. Clear all grid cells
2. Clear current cell
3. Open current slide/cell in a new viewport tab in a 1×1 grid ​