This is from EG7 document "
1
Take the Photo Specifications sheet (found in Appendix B of the Visa Office specific instructions) to a photographer.
2
Ask the photographer to provide you with six photos of yourself and each family member.
3
On the back of one photo for each person, write the name of the person appearing in the photo and his or her height and eye colour.
4
Enclose the photos of each person in an envelope and seal the envelope.
5
Write your name and date of birth on the outside of the envelope.
6
Staple the envelope to your application form. Be careful not to staple or bend the photos."
yes put photos in an envelope and staple to form
see paragraph 2 on http://www.canadainternational.gc.ca/buffalo/imm/federal_worker_hints-conseils_travailleur_federal.aspx?lang=eng
for extra safety i am writing name, dob and file # on each photo just in case they mix them up.