Neos\Media\Domain\Model\Thumbnail::initializeObject PHP Method

    public function initializeObject($initializationCause)
    {
        if ($initializationCause === ObjectManagerInterface::INITIALIZATIONCAUSE_CREATED) {
            if ($this->async === false) {
                $this->refresh();
            }
            $this->emitThumbnailCreated($this);
        }
    }