The Six Types of Perceptual Connection

There must be a direct sensory connection, or causal link, between the object of perception and the perceiver. But what about seeing something in a mirror, through binoculars, or through a video camera? It seems clear that Gautama has not said enough to explain this sort of connection involved in perception. Niyya point of view insists blueness is objectively out there in the world so I should be able to perceive it.