This will surface the clipboard on the right hand side of your screen, showing your added resources:
If you click away from the clipboard or select 'Close' in the bottom left hand corner, the clipboard menu will hide itself. You can return to it at any point by selecting the clipboard icon in the top right hand corner menu:
The number shown will help you keep track of how many items you currently have added to your clipboard.
The clipboard will remain available to you even if you log out and come back to the site later. Clipboard content will only disappear if you select 'Clear clipboard', or if you use the 'share' or 'add to lesson' options.