Yes, they can offer it, but then that becomes taxable too, so they'd have to inflate that as well by an estimated tax rate (probably mid-20%s).
But there is no incentive to the Company to do that other then generosity (ha!), especially since the prizes are usually marketing gimmicks from a third party partner.
Companies do that sometimes with employee bonuses, especially with relocation (not exactly the same, obviously, but rough idea).
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