Can't access Photos for attachments in drop down menus
I have a 27" iMac (late 2013) which I recently upgraded from Yosemite to Sierra version of OS X. Prior to this upgrade, I was able to access Photos via drop down menus in contexts such as making an attachment to an email in the Mail program, or in Safari when making an attachment to a web form. After the upgrade, I only seem to be able to access drive folders, but Photos and PhotoBooth have disappeared from the list. Can they be restored, and if so, how? If they can't, how am I supposed to attach photo content to email messages, Facebook posts &c? I know you can add email accounts or Facebook accounts directly to the OS and then "share" images that way, but this doesn't cover all use cases and is a very counter-intuitive way to work. This is my own content, I should be able to access it for attachment.
iMac, macOS Sierra (10.12.1)