Could you please advise me on the meaning of 11th paragraph
of a BBC article "making a comic book"

Whole article can be found here.
BBC News - Comic book styles from around the world

On the 11th paragraph, it says
"Because they (Japanese comics) are so long, you can get things like a bead of sweat
on someone's forehead moving downwards over three pages
," adds Pilcher.

Can I understand the red coloured part says:
"Because Japanese comics are so long, you have to read three pages very quick" ?

I'll be grateful if you could explain the context of this part.

Thank you in advance,