You can remove any attachment from the toolbar section of TheBrain.
Tap the attachment icon in the toolbar section of TheBrain or tap the Thought icon to access the Attachments page.
Tap the icon next to the attachment you wish to delete. You can also tap Done if you change your mind.
Tap Delete to remove the attachment.
Tap Done when you are finished removing attachments, then tap anywhere outside the Attachments menu to return to your Brain.