It is the framework which changes with each new technology and not just the picture within the frame.

The line restates a core McLuhan idea: new media and technologies do not merely deliver different “content” (the picture), they alter the underlying conditions of perception, attention, social organization, and meaning-making (the frame). In McLuhan’s terms, the medium itself reshapes the scale, pace, and pattern of human affairs; focusing only on messages obscures the deeper transformation of the environment in which messages are produced and received. Read this way, the quote warns against treating technological change as superficial substitution. Each major medium—print, radio, television, digital networks—reconfigures what counts as knowledge, authority, privacy, and community by changing the structure through which experience is organized.