I don't know, you tell me. And while you're at it, give me the size and shape of a photon. Pick a wavelength, any wavelength. Scratch that ... if a photon is a point particle it really can't have a wavelength, can it, because that would imply something which varies with distance?
You're asking ill-formed questions. They don't make physical sense.
Nature, at its core, is quantum mechanical. Electrons behave like electrons; photons behave like photons; quarks behave like quarks. Everything you think you understand--sound waves, water waves, billiard balls, butter--is composed of those quantum objects. Their properties are derived from the properties of the quantum objects that compose them.
Now you demand that quantum objects and properties be described in terms of quotidian objects and properties, but it can't be done. It it philosophically impossible to describe the more fundamental in terms of the less fundamental. It works rather the other way around.
Meanwhile, if you want to understand how a photon can be both pointlike and wavelike, study the Fourier transformation.
I don't know, you tell me.
I can't. It's a nonsensical question. Just like the size and shape of a photon.