Chapter 5, upon returning home what does Nick notice about Gatsby's house?

From the text:

When I came home to West Egg that night I was afraid for a moment that my house was on fire. Two o’clock and the whole corner of the peninsula was blazing with light, which fell unreal on the shrubbery and made thin elongating glints upon the roadside wires. Turning a corner, I saw that it was Gatsby’s house, lit from tower to cellar.