Strictly spoken, a waveform can't work as complete design spcification, because it tells only about specfic cases. In the present case, we can only guess, that the circuit performs a pulse extensions of 2 clock cycles under all condtions. There must be a describing text.
Secondly, the waveform must be unequivocal. The shown one is just the opposite, showing a timing that can't be implemented in a real circuit, because input edge, clock edge and output edge seem coincident. It seems to have been sketched carelessly, without considering real logic behaviour.