NSW Premier Mike Baird said the siege last December had forever changed Sydney, whose residents mourned the deaths of Tori Johnson and Katrina Dawson in the face of evil.
Mr Baird said the kindness of thousands of people who left flowers and cards in the days after the siege was "something quite incredible".
"We saw this outpouring of compassion and mourning that came with those families and victims," Mr Baird told reporters in Sydney on Sunday.
"It also said to those that want to bring hate, we're going to respond with love, we're going to respond with peace."
The design of the 'maquettes' for the Sydney siege memorial (Photo: NSW Premier's office) Source: Supplied by Danyal Syed
"And those that come and try and divide this city, this state, this country, well you won't, we're going to unite," he said.
Stylised flowers set inside mirrored boxes would be lit in the popular city thoroughfare day and night, designer Richard Johnson said.
Mr Johnson said he hoped the "quiet and reflective" tribute would encourage Sydneysiders to pause and take stock.
"The impact will change as you change your view of each work," Mr Johnson said.
"The reflection of the sunlight or the night light shifts and the reflection of the stylised flower within the mirrored box will shift."
The design of the floral cubes that will be inlaid into the granite pavings at Martin Place (NSW Premier's office) Source: Supplied by Danyal Syed
Mr Baird invited the people of Sydney to attend a twilight ceremony on Tuesday marking the one-year anniversary of the siege.
"My hope is on that day we focus in on what brought us together rather than those forces that try to drive us apart," he said.
