In this episode of The Complete Picture (How to Link Smart Objects in Photoshop CC), Julieanne will show you when to embed and when to link Smart Objects, update modified content, resolve missing files and filter based on smart object attributes.
• Option + (Mac) | Alt + (Win) drag and drop a file from Bridge to an open document in Photoshop to create a linked (not embedded) Smart Object. Note: this shortcut will also work if you drag and drop from Lightroom into an open Photoshop document on the Mac.
• Command + Option + Shift + E (Mac) | Control + Alt + Shift + E (Win) will edit the contents of a Smart Object.