There are so many microcontrollers which could be packed behind this, in a sandwiched way, behind the CCD which captures the light. Think of the stuff that's on

There are so many microcontrollers which could be packed behind this, in a sandwiched way, behind the CCD which captures the light. Think of the stuff that's on your Smart-/Chipcards, like Credit/Debit/Banking/ID/Drivers License/... The thing under the golden metal contact plate has a diameter of about 5 millimeters, yet it is able to perform a subset of something like Java. The same goes for the SIM in your phone, or a Micro-SD Card. There the Microcontroller serves the interface on one end, and acts as a RAID-controller for the arrays of NAND-storage on the other end. This can all be hidden behind that, layered underneath each other. The biggest thing would be battery to power it, or the coils to harvest energy from WIFI, or whatever. Combine that with circuitry which only wakes up the system when the image is changing, and your're good to go, ...err spy ;->