I don't know how I can share assets across workspaces.
I found that we can share a folder, when I click right on folder, I don't have any feature to make it shareable. screen shot below
"Global Emails" may be a system folder, you will need to create a new folder. Another possible reason is that there needs to be assets in the folder in order to share. You can move the assets to the folder and then share the folder.
You will need to create a folder for each component.
For example, you will need to create a new folder under Template folder, right click and then the Shared folder option will be available then.
Also, you can only share the following:
Can images still be shared?
I have a user trying to access an image in another workspace. The image folder within the other workspace is shared with him.
But while editing the email, and swapping a banner image, the shared workspace image is not searchable.
Also, Marketo docs does not mention that images are shareable...