That comment in her article doesn't give a lot of context about what kind of answer she might be expecting. But certainly this is by now a well-known and venerable question about which much is already known. The Wikipedia page on the holographic principle has a good overview. The most counterintuitive thing about the holographic principle is that it says the information capacity of a region should be proportional to its surface area; if you think of information capacity in terms of how many tiny two-state devices you can pack in there, you'd expect the interior volume to be the limiting factor.

That comment in her article doesn't give a lot of context about what kind of answer she might be expecting. But certainly this is by now a well-known and venerable question about which much is already known. The Wikipedia page on the holographic principle has a good overview. The most counterintuitive thing about the holographic principle is that it says the information capacity of a region should be proportional to its surface area; if you think of information capacity in terms of how many tiny two-state devices you can pack in there, you'd expect the interior volume to be the limiting factor. That intuition holds true up to a certain point, but eventually the concentration of mass-energy, putting aside quantum miniaturization issues, becomes so great that a black hole forms. Roughly speaking, by a bit of dimensional analysis and the fact that gravity is an inverse-square law, it's radius squared (proportional to surface area) that's the relevant quantity here.