When using the Bcc field, recipients ought not to see the names or email addresses of other recipients being sent to.
It is unprofessional having images pasted into the body of a business email. I've seen it both as sender and receiver, and I was unable to see the images sent to me by a business correspondent. My email system blocked the incoming images.
When adding a photo to a reply or a new email in the Outlook mobile app, I want to attach it so the message doesn't look so cluttered, and also the recipient can decide how to handle it