Google has “When your Google+ photos match certain criteria”.
Two possibilities are Motion and Mix, which can be selected manually, though only via an Android device. “Take at least 5 sequential images of a similar scene with movement and Google+ will make a short animated and looping image from them.” and “Take several portraits with similar backgrounds or scenes and Google+ will put them together in a photobooth-style grid. This is meant to showcase a group of close-up portraits.”.
Other possibilities are also dynamic eg snowfall – presumably when there is a lot of light colour low down in the image - and twinkling. “when you take a photo of something that shines - like lights, a Christmas tree, or a starry sky - Google+ will automatically create an animated GIF”.
For a while at least :-) images might be “Hoffed” dynamically (according to).
Static possibilities include:
• HDR: If you upload multiple images of the same scene with different exposures -- low, normal, high -- Google+ will merge them together to form a picture with better contrast and clarity of all parts of the scene.
• Smile: Take multiple photos of a group of people, Google+ will attempt to choose the best shots of each person in the image and merge them into a single photo with the best elements of each.
• Pano: Take a series of photos panning across a scene and Google+ will stitch them together into a single panoramic image. (Useful for stand-alone cameras without a pano mode.)
(ibid where While there aren't any strict rules for what gets made into an Auto Awesome and what doesn't, looking at the guidelines above you can get an idea of how to make each one appear.” is also mentioned.)
So, I speculate:
- For the dynamic possibilities, lots of similar images, or
- bright spots and/or light colour in the lower part of the image.
- Pictures of people, with easy facial recognition (and teeth visible).
- Similar images (different exposures) for the panoramic and/or image enhancement possibilities (the latter seemingly capable of very impressive results).
- Some degree of giving everyone a chance to have their image awesomed.