Q. How do I get a photo for my Azure AD users that are replicated from Active Directory?
A. Providing you have the Exchange schema extension configured on your Active Directory there is a thumbnailPhoto attribute which is replicated by Azure AD Connect and will become the photo for users. See FAQ "How can I easily set the image for an AD user" at http://windowsitpro.com/windows-server/set-image-user-ad for the PowerShell to set the attribute.