The ECAM SPEED BRK memo flashes amber if:

The ECAM SPEED BRK memo flashing amber indicates that there is a specific operating condition that requires the crew's attention. When speed brakes are extended while thrust is above idle, it creates a potential risk of exceeding the aircraft's operating limits. The speed brakes are designed to be used primarily during descent or landing phases, where the thrust should typically be at idle to effectively reduce the aircraft's speed.

When thrust is above idle at the same time the speed brakes are deployed, it can lead to unexpected aerodynamic behavior and increased drag, which could jeopardize safe flight operations. Thus, this condition warrants immediate attention from the flight crew, reflecting the flashing amber memo as a warning to ensure adherence to safe operational practices.

The other choices relate to different operational scenarios that do not trigger the amber memo under these specific conditions. For example, hydraulic pressure being low or the loss of spoilers might indicate mechanical or system failures but do not specifically correlate to the deployment of speed brakes with thrust above idle. Similarly, the scenario where speed brake deflection does not match the handle position may indicate a malfunction but is not the same triggering condition as having thrust above idle while the brakes are extended.