The present disclosure describes techniques of processing information flow and synchronously displaying image s, mask frames and comment information. According to the present disclosure, a system processes a first information stream uploaded by a stream pushing terminal to obtain a frame image and mask frame data, the mask frame data corresponding to the frame image and identifying a timestamp offset indicative of a time difference between the mask frame data and a playing timestamp of the frame image. The system synthesizes the frame image and the mask frame data to generate a second information stream; and output the second information stream to a client for synchronously displaying the image frame, a corresponding mask frame, and the comment information.