Google once again points out a feature the Pixel 3a has and the iPhone XS doesn't

The point of these ads is to point out that such features as Night Sight and AR navigation are available in a phone starting at $399 as compared to the $999 it costs for the 64GB iPhone XS (aka "Phone X"). Meanwhile, AR navigation on Google Maps is not to be used while driving, and to make sure that users don't become too distracted, they will be reminded to put the phone down after a certain time. If the user doesn't obey, the screen will go dark. This will also preserve battery life on the phone since AR navigation is a big power consumer.

Besides showing pedestrians how to walk from point "A" to point "B" with arrows superimposed on real-world images, AR in Google Maps will also point out famous landmarks and certain retail locations. It isn't clear whether Google has rolled this feature out to all Pixel models yet. But let's say that a Pixel 3a user has opened Google Maps to help him or her navigate while walking. If AR navigation is available, a button will appear that says "Start AR." At that moment, the regular Google Maps UI is replaced with the real world backdrop from the phone's camera.