So the red stamps on the prints are ownership marks?
Typically the marks in red are the artist's seal. Publisher and censor marks would also appear on prints, but tend not to be red.
Is that supposed to be Mt. Fuji in the background?
Yes, it is! The artist, Katsushika Hokusai, became famous for his 46 depictions of the mountain.
The blue used in this print was a new type of chemical pigment called Prussian Blue. It was developed in Germany accidentally in 1829 and had a huge impact in the arts—even as far away as Japan!
This is the type of print that had an enormous impact on French painters in the 19th century, such as Monet (whose painting of the Doge's Palace hangs on the other side of the exhibition).