An aluminium dummy of the Pixel 6a has shown up online. It shows us that the phone will look similar to the vanilla Pixel 6, complete with two rear camera sensors and an under-display fingerprint sensor.
https://www.notebookcheck.net/Pixel-6a-dummy-highlights-key-design-elements-including-a-prominent-camera-bump-and-no-3-5mm-audio-jack.583432.0.html