Not every comparison is pure whataboutism design to pull the discussion off-topic or complete off-track.
Perhaps the difference is so obvious to you that the question doesn't even need asking, but I think it is a valid question: what values does this invasion violate that the other situations do not, at least not to the extent that McD reacts by considering pulling out completely.
It would undeniably be whataboutism if it were McD being asked why they've done (or not done) something and they're point out something unrelated (or only tangentially related) that they have/not done or asking about what other bodies have/not done in that area of discussion. But as an outsider looking at McD, asking them to define their position more precisely, perhaps with reference to their position in what may be seen as similar circumstances, feels like a valid request rather than the fallacy of whataboutism.
Of course the question could be used purely to make McD look bad, particularly if the asker of the question as some axe to grind (against McD specifically, American corporates more generally, or big business even more globally), which flips the pendulum back in the direction of a logical error because the asker is not actually trying to gain perspective but is instead intending to impose that others take their perspective.
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FWIW I think I have a fairly solid idea of what the difference is. If you remove the moral aspect and just look at the circumstances from the robotic PoV of a business doing business: while the sanctions don't directly affect McD their impact does affect their ability to efficiently do business in Russia. Such sanctions don't exist in a manner that affects them in the same way in those other situations. Moving away from purely robotic business related points, this is happening in Eastern Europe not the East so it is both closer to home to those making decisions and is getting a lot more attention in Europe and the US (meaning that there is more push from their customer base in the west).
