Seven was produced by New Line Cinema, a Time Warner Company
New Line Cinema might as well be Old Line Cinema at this point, having produced movies since the 1960s. Along the way, they've produced cult hits like John Waters' Pink Flamingos (1972) and The Texas Chain Saw Massacre (1974) before becoming a house of blockbusters, producing all 18 of Peter Jackson's The Lord of the Rings movies (give or take a dozen) and comedies like Tammy (2014) and Horrible Bosses (2011).
They were still taking risks in the '90s. The studio released 13 films in 1995 alone, including the live-action version of the video game Mortal Kombat and Ice Cube's Friday. (So, if it weren't for New Line Cinema, we wouldn't have "Bye, Felicia.") Seven was their most commercially successful film until Jackie Chan kicked it in the nads with Rush Hour 2 (2001), despite the studio's best efforts to ruin the movie.
How did they try to ruin it? By changing the pitch-black ending. The studio did not want Gwyneth's head in the box. We picture the conversation going like this: "How about a DiGiorno Pizza instead? Think about the tie-in opportunities! It's not Gwyneth's head; it's DiGiorno!"
Actually, their idea was even more stupid than a pizza. They suggested that the box contain the head of a family dog instead of a Paltrow, but Brad Pitt said he wouldn't do the film if that was the idiotic ending.