It does expect you to pull a lot out of context. I will admit I probably mentally filled in the blanks due to familiarity with the original, which I just rewatched on Halloween, as well as having read Dracula probably 10 or 15 times since 7th grade.
As far as “mixing” Dracula and Nosferatu, that’s simply by default. Nosferatu is an unauthorized adaption of Dracula (the novel) that Murnau tried to skirt by changing some character names. Didn’t work, and he got sued and had to pay Stoker’s widow. Also, all copies were supposed to be destroyed but a few incomplete ones survived, so basically it exists today as a bootleg.