Do you have a date for the photo? The Tor Scots were authorized a regimental flash, but it is not like this one. See http://www.servicepub.com/helmetflashes.htm. The Tor Scots private does not have a division patch on his tunic, while the officer has the officers' 2 CID patch.
Not sure what you mean by a dragoon? The soldier with the rampant lion decal on the helmet is wearing Toronto Scottish shoulder titles. The Toronto Scottish were the MG support battalion in 2 CID. The officer is wearing a great coat with the 2 CID patches.