The "I Have No Idea What I'm Doing (LOL)" meme is a collection of animals and people put into normal, everyday situations while looking extremely unnatural doing them. With the dogs/cats, it's usually the case that they're anthropomorphized in some way. Dogs doing construction work, cats doing science, a dog doing science, dog photographers, and even cats using computers -- this meme is a great combination of adorable pet pictures and a great point: the animals all have absolutely no idea what they're doing. As far as they're concerned they may as well be in a pool, some mud, or on a couch.
Animals have no idea what we're doing most of the time and when we prop them up, dress them up or take pictures of them, they have no idea what's going on. And that, conceptually, is hilarious. A picture of a dog with "I have no idea what I'm doing" written on it is hilarious because not only does the dog's face confirm that fact, but it's something you never really think about when you see an animal pose for a photo. They have no idea what the hell is happening.
Originating with a picture of a dog taking a photograph of a wedding party with "I have no idea what I'm doing" written on it, this "I don't know what I'm doing" meme took off on Reddit after a while due to everyone's love of not only dog/cat photos, but the insane amount of ridiculous pictures of them doing human things people leave all over the internet. After that, the popular caption started being attributed to just about any picture of an animal facing a camera, looking like they're doing something human. It then became an Image Macro. The Image Macro now has a life of its own, making it a meme.
So enjoy the very best of the "I Have No Idea What I'm Doing" meme, in all its glory.