Astrophotography: Capture the night sky in detail like never before
Good results clearly depend on having the higher-end phones in the Pixel family so that the processing can take advantage of better hardware. Unfortunately for me, my phone is a Pixel 3a XL (nearly 3 generations old), which does not contain the GPU accelerator needed for really deep shots, so I have not-so-impressive results. In the comparison examples below, the Pixel 3a XL image in the middle was a four-second shot (max on my phone in astrophoto mode) at ISO 1,157 with the lens info recorded at f/1.8. Both of the flanking shots were at ISO 1,600 at 30 seconds (maximum length allowed internally) with f/2.8 lenses on dedicated cameras. While these quick shots (taken over-shoulder of my main scope) are not exact 1:1 comparisons, they give you an idea of what is possible with a low-end Pixel phone versus “normal” cameras. Source

Titan M Chip: Making your phone secure and private
At its most basic level, Google’s Titan M is a standalone security focused chip that sits alongside the main processor. In the Pixel 3’s case, it’s paired up with the Qualcomm’s Snapdragon 845. The chip’s primary function is to verify the boot conditions for starting up Android, ensuring that it hasn’t been tampered with at a low level. The Titan M verifies the signature of its flash-based firmware using a public key built into the chip’s silicon. In other words, there’s now a separate hardware component to Android Verified Boot in the Pixel 3, which is an updated Project Treble compliant version of Verified Boot that has been around since Android 4.4. Or as Google puts it, the chip is designed to “make sure that you’re running the right version of Android.” Another way the Titan M does this is by preventing code from unlocking the bootloader, meaning that malware can’t gain access to the lower software-levels of your device. It also won’t allow malicious attacks to rollback Android to an older, less secure version. Source

Rear fingerprint scanner: Swipe to toggle notifications or simply use to unlock your phone
Soniya Jobanputra, a product manager on the Pixel team, told the PA news agency that the move away from the face unlock system is for a "good trade-off" to make way for other premium features on the Pixel 5. "When we set out on Pixel 5 what we really wanted to accomplish was get you a 5G device that still felt super-premium and didn’t feel like you compromised on anything, and so what we had to do to accomplish that was literally stack rank what we find users find most useful," she said. It seems that the main reason for this is because it is potentially more secure. Jobanputra went on to say "and so as we looked at that list face ID is awesome and it’s a great tool for unlocking your device, but you know what, a fingerprint sensor can meet those needs as well, just as efficiently, just as fast and in some cases even more securely". She continued: "We really felt that it was a good trade-off for users to go with the rear fingerprint sensors so that we could enable some of these other premium features that users are looking for in a device." Source