How do I tap multiple images to share them all at once with iCloud Photo Sharing?
Indeed, the screenshot does appear to have been edited.

The correct way to select multiple photos is to press the Select button, then tap the pictures.

As far as I know, it is impossible to select images without pressing the Select button, and pressing the button changes it to a Cancel button, and the navigation bar title changes to Select Items (or the number of items selected), as well as removing the back navigation button.



On the left: Apple's screenshot; On the right: how it should appear when selecting multiple pictures.