Answer
For a permanent-residence application in Uruguay, the guideline is one or two colour photographs per applicant, approximately 3 by 4 centimetres. Requirements also refer to a white background.
A photograph may seem minor, but it is part of identifying the applicant, so prepare it in advance with passport copies and other identity documents. For a family application, count photos separately for each person.
To avoid a format-related delay, it is sensible to have two identical 3-by-4-centimetre photographs on a white background for each applicant. If the office takes only one, the spare may be useful for related steps that also require a photo and renewed identity verification.