The illustration shows the hand signal (thumbs up) for unconditional consent. It indicates that a proposal fully meets one’s own expectations and that there are no reservations or requests for changes. In the consent process, such hand signals serve to make the stance of all participants clear quickly and transparently. Unlike traditional consensus, however, full approval is not a prerequisite for a decision. The only decisive factor is that there are no serious objections. The hand signal therefore indicates the level of support, not the validity of the decision.
Source: See here