Low-power wireless video sensor nodes play important roles for applications in machine-to-machine (M2M) network. Several design issues to optimize the power consumption of a video sensor node are addressed in this paper. For the video coding engine selection, the comparison between conventional video coding system and distributed video coding (DVC) system shows that although the rate-distortion performance of existing DVC codec still has room to improve, it can provide lower power consumption with a noisy transmission channel. Furthermore, it also demonstrated that video analysis unit can help to filter out video contents without event-of-interest to reduce transmission power. Finally, several future research directions are addressed, and the trade-off between the video analysis unit, video coding unit, and data transmission should be further studied to design wireless video sensors with optimized power consumption.