It's not just pictures though, it is what you are looking at and perceiving.
If you look up into the sky tonight and see a supernova you are not seeing that point in space as it is, you are watching something that happened however many light years ago. You are witnessing the past.
If an alien spaceship is right this moment sitting approximately 8 light-years away and watching the earth, and New York, on its super telescope it may well be witnessing the twin towers being attacked and destroyed, it would be watching earth vintage September 2001 despite being out there looking right now.
And yes, you are 'hearing back in time' with regards to the shout. You are hearing something that happened a second ago. On the other side of the field the sound there is not the one you are hearing, time has moved on since it was made.
In essence nothing in the world you perceive can be considered the present. Everything around you is an image of the past, of things that happened a fraction of a second ago and travelled to your senses and into your brain. By the time you register the world around you it is no longer reality anymore. To quote another famous bearded guy; "You're living in the past man!"