A method for communicating an image stream, one embodiment comprising negotiating, between a server and client, an MTCC identifying: a window as a portion of a display of the client, and an occluded portion of the window defined by the client; generating, by the server, complying with the MTCC, a sequence of image frames each comprising pixel data in a portion of the frame identified by the occluded portion; transmitting an encoding of a first frame of the sequence not including an encoding of the pixel data in the portion of the first frame; identifying, by the server, an event associated with the sequence; and transmitting, before communication between the server and the client regarding the event, by the server, information of the event in conjunction with an encoding of a second frame of the sequence including an encoding of the pixel data in the portion of the second frame.