"#GameOfThrones coffee in episode 4 and now a water bottle in the finale #GameofThrones #GOT," wrote one user on Twitter on Monday.
While one bottle popped up behind Samwell Tarly's foot, eagle-eyed fans discovered another water bottle behind Ser Davos' chair.
"...First Starbucks now a water bottle this show is a joke #GameOfThrones #GameOfThronesFinale #TheFinalEpisode," wrote another Twitter user.
"When the writers just want to get over the show and leave a water bottle in the scene #GameOfThrones #watergate2019 #GameOfThronesFinale #starbuckscup all over again," wrote another.
The bottles popped up more than once over the course of several minutes.
HBO network said the coffee cup that appeared in the fourth episode of the final season of "Game of Thrones" was a mistake,
"The latte that appeared in the episode was a mistake. Daenerys (the character Daenerys Targaryen played by Emilia Clarke) had ordered a herbal tea," the company said in a statement, reported variety.com.