An enemy with several reconnaissance aircraft can test a ship's disguise repeatedly. Aircraft carriers and Town-class cruisers provide examples because they can operate multiple aircraft. Fooling the first flight does not guarantee that a second, third, or fourth will accept the same identification. Each sighting increases the chance of a closer inspection, making the deception a short-term expedient. Large numbers of modern drones could create the same difficulty.
Notable Point · 5:18-6:08
Why repeated reconnaissance could expose Graf Spee's disguise
Carriers and Town-class cruisers could send several reconnaissance aircraft, increasing the chance that a later flight would approach closely enough to expose a disguise.