Original sentence: For instance, Carnival Corporation owns both Carnival Cruise Lines, whose former image were vessels that had a reputation as "party ships" for younger travelers, but have become large, modern, yet still profitable, and Holland America Line, whose ships cultivate an image of classic elegance
Edited sentence: For instance, Carnival Corporation owns both Carnival Cruise Lines, whose former image were vessels that had a reputation as "party ships" for younger travelers, but have become large, modern, and extremely elegant, yet still profitable, and Holland America Line, whose ships cultivate an image of classic elegance