+1(514) 937-9445 or Toll-free (Canada & US) +1 (888) 947-9445
The front and back are on one page, and the second photo is on the second page—2 pages of 1 PDF.
 
@theclaimer Thank you very much. The link says photo must be in Jpeg or PNG format. For online application, the photo must be submitted digitally I guess. It looks like we can submit photo in both jpeg and pdf format for online application. Please correct me if I am wrong.
 
As of now, only online application is accepted for PR applications. There are two types of ways to submit photos.
1. Printed photo which you need to scan according to the specification (please see the pixel in the link)
2. Digital photo ( I have no idea about it, but some people use digital photos, maybe it is something like a link or soft copy of those photos)

I am sure about the printed scanned one because I submitted my like that.
 
@theclaimer Thank you very much for your help. This is what I am going to do. Hopefully this will meet all the requirements
1) 1 Photo front in jpeg format
2) pdf containing 2 front and 2 back of photos (4 pages)

I will have two files for each person and will be within their allowed numbers.
 
You need to submit
- 1 photo with front and back
- 1 photo only front.

The way you mentioned it will count 3 photos.

It's your call what you'll do. I just shared my experience. Good luck!
 
@theclaimer Thanks for your help. I think submitting 3 will not hurt. In the background declaration, do we need to disclose all our membership back home?