Not without decapping -- these are bare-die parts, of course. Usually CSPs, but many CPUs are included, which seems to be what they're looking at here. They're also flip-chips, so the substrate is what's presented, allowing long enough wave IR to peer into the active region, the transistors themselves -- well, not really, the wavelength spans dozens of actual transistors on today's finest pitch processes, but the reflection still depends upon the density and pattern of transistors, trenching and doping, so you get that.
The pros use it, plus direct emissions, to investigate their own chips -- malfunctions can emit light (unintended minority-carrier hijinx) or even locally heat up (thermal emission), greatly reducing exploration time on the SEM, let alone cutting (FIB), sectioning and TEM. Or other tweaks; maybe you can hit parts with light of suitable wavelengths and cause effects -- kind of the microelectronic analog to hot and cold spray when testing ye olde discrete circuits.
Tim
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