The top tool bar in the Editor is all about importing/downloading and naming images.
The items from left to right are as follows:
Add an image: Opens the “Edit an image from…” chooser to add to your current project.
Edit a copy: Opens a new copy of your image, while preserving the original in Hub.
Download: Saves your image to your computer. See: Downloading Images to Your Computer.
Share: Sends image to email, social channels, or lets you invite others to a Shared Space. See: Sharing Images from the Editor
[FILENAME] Drop-down: Let’s you rename your image.
Changes saved/Saving now: Shows the status of your file’s auto-save to Hub. See: Your Projects Auto-save as You Work