Some fans groused at the faux pas, reminding their Twitter followers that it took two years for the final season to be filmed and aired, CNet reported.
Others took a chance to poke fun at not only the apparent mistake, but also some of the naming conventions of both the show and Starbucks.
The Verge reported that it is not clear whether it was a mistake or an Easter egg that would get people talking the next morning.
On Monday, “Game of Thrones” art director, Hauke Richter, admitted it was a coffee cup, but it wasn’t from Starbucks latest Winterfell franchise.
It was a coffee cup from a local coffee shop in Northern Ireland, TMZ reported.
"We are usually so diligent that this does not happen. The shoot was very hard and demanding and it is likely that after a very tiring episode three shoot, this was simply overlooked by an exhausted crew," Richter explained.
HBO also owned the mistake, cracking a joke on Twitter.
According to the Hollywood Reporter, the cup has been digitally removed from the episode on HBO Go.
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