How to reproduce:
Compose email, add picture inline

Actual results:
After selecting the picture in the Windows Explorer/Finder, image appears in the open window, but there is no button saying "Continue" or anything similar. (The button "add image" on the right only opens the Windows Explorer/Finder again in order to select another picture)

--> The user has to know somehow respectively "guess" that he needs to click on the picture again in order to proceed!
Not all users will have this idea. They expect a button which makes it obvious that this is the way to continue. Yet there is only a "cancel" a button.

Expected results:
On the left side of the "Cancel" button, there should be a (green) button saying "continue" or anything similar. When this button is clicked, the same view should appear which currently appears when you click on the picture again.