When your industry or business gets changed on its head because you didn't see or act in time to the changes coming (Kodak didn't react in time for digital cameras; and bang, went broke)
I've had two notable Kodak Movements. Once I crapped a turd the exact size and shape of a banana,including the stem. The other was a perfect pooquestion mark. A honorable mention goes to the one that looked like an Indian tomahawk.
An moment that is so beautiful, incredible or downright hilarious that it deserves to be preserved with a picture, and yet no one present has a camera with them.