Amazon has two buildings in Bellevue right now: Center 425 on 4th and 106th and the old Expedia building on 4th and 108th. Maybe they mean the Expedia building?
The other link is about a new building Amazon's putting up. There are a couple right now, both next to the Bellevue Transit Center on NE 6th St. The one is on the 108th St. side. If you're looking for a construction site, it's probably that.