Why is Normal Area to Light Rays Invariant?

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It is a fact that all inertial observers would measure the same area normal to a beam of light rays in relativity. You can prove this by considering the displacement vector connecting a light ray to its neighbouring light rays. But I wondered if there were some intuitive explanation of why this must be true?
 
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Not really sure what you're looking for. Length dilation/time dilation?
 
Thread 'Can this experiment break Lorentz symmetry?'

Thread 'Can this experiment break Lorentz symmetry?'

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Thread 'Relativator (Circular Slide-Rule): Simulated with Desmos - Insight'

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