So when I first started my little Glitch exploration, I got the quest to find a shrine for each Giant and donate there. Of course, the first time you donate to a Giant's shrine you see a picture of them along with some descriptive text. They looked so familiar, but it took me a long time to realize what they were reminding me of!
But I've got it! They look like the works of AJ Fosik, an amazing artist who makes, among other things, beautiful, colorful "masks." You can see his work here: http://ajfosik.com/ It's so crazy how similar the Giants look!
Though it isn't one of his masks, this is actually one of my favorite pieces of his work: http://www.flickr.com/photos/ajfosik/6282201592/in/photostream Check his stuff out, it's so rewarding to find new artists. :)