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.
These staged photos are always a pain. I know that black and white photos can play havoc with true colours, however, the insgnia on the photo (my best guess) seems to be red on yellow background.
Do you have any information on the origins of this photograph? Place and date would be quite helpful.