Two Photographs, Size Unstated
The count is published; the millimetres are not.
The Ministry of Foreign Affairs lists what a visa request must contain, and the second item reads: filling in a visa application form with two photographs. That settles the count.
It does not settle the size, because no dimension appears anywhere on the page. This site shows the 35x45mm frame because that is the figure Iraq publishes for its own passport photograph — a reasonable default from the same authority, but not something Iraq has said about visas.
We would rather tell you that than print a number and let you assume it was checked. If the mission handling your application publishes its own figure, use theirs.