[H2O]

Full mock-ups don't usually happen until well after site mobilization. They are as much about studying how different materials come together when installed as they are about individual materials like glass. They are a tool for the architect to make sure the contractor understands how those materials need to be installed and for dialogue and problem solving if they do not come out as envisioned. The components get installed step by step as the real construction proceeds. It is possible they are taking advantage of an adjacent site to start the mock-up early, but it sounded like this was just glass and not a full mock-up.