An "attentive viewer" refers to someone who pays close attention and focuses on something they are watching, such as a TV show or movie. Full definition
Quieter moments of exposition will reward attentive viewers with clues to the conspiracy, while occasional chase sequences and gunplay will break up the more demanding components into digestible pieces. (hoopla.nu)
An enthrallingly dense and topical political thriller which rewards attentive viewers. (metacritic.com)
However, the plot moves at an excruciatingly slow pace that would challenge even the most attentive viewer from falling asleep. (metacritic.com)