It seems that Google is looking to improve on that experience as they have announced an updated to the Photobooth feature on the Pixel 3 where it now is able to detect kisses made towards the camera.
According to Google, “Once you enter Photobooth mode and click the shutter button, it will automatically take a photo when the camera is steady and it sees that the subjects have good expressions with their eyes open. And in the newest release of Pixel Camera, we’ve added kiss detection to Photobooth! Kiss a loved one, and the camera will automatically capture it.”
Google also notes that they worked with photographers in identifying expressions that could be used to trigger capture. “We worked with photographers to identify five key expressions that should trigger capture: smiles, tongue-out, kissy/duck face, puffy-cheeks, and surprise. We then trained a neural network to classify these expressions.” For those wondering why this sounds familiar, it is because this is similar to the tech that Google used for its Clips camera. The update to the Pixel 3’s Photobooth should be live so do keep an eye out for it.