The flag of New Zealand (from 1902) and the flag of Greece (from 1978). The New Zealand flag used here has a 1:2 ratio and the Greek flag a 2:3 ratio, resulting in the Greek flag being rather wider than the New Zealand flag when both flags have the same length, as here. (Use of this image or either flag in it in connection with either New Zealand before 1902 or Greece before 1978–present would be anachronistic. Although both flags are older, the specific combinations of proportions shown here were not officially in use for "land" purposes until the late 20th century.)
Own work based on: Flag of New Zealand.svg  and Flag of Greece.svg
This file was derived from:

 Flag of New Zealand.svg
Flag of Greece.svg