Stuffed Flex Hose
No. This image is not electronically touched up to make the lint buildup look worse. This is an actual transition hose that—under normal operation—had lint accumulate on the inside to the point where it became a severe fire hazard.
This is a natural occurrence and is shown to highlight the importance of monitoring your dryer's exhaust for safe efficient operation. Across the US alone, the vast majority of dryer fires (over 15,000 each year) are the result of exhaust problems like you see here.