Someone sends me an email containing a photo. The photo is small not full size.

Apple Mail 12.4

Mojave 10.14.5

Incoming emails may contain a photo but it's quite small, not full size. If I pretend to forward the email the photo becomes large, filling the text area. I want to see photos that are sent to me full size without having to pretend to be forwarding them first. I don't see any choices in the Preferences to change this.