Yes, correct, but not specifically related to takeoff.
It is derived from the respective engines EEC and indicates the maximum thrust that the EEC has computed it can deliver (based on current ambient conditions) if you advance the thrust lever to the full forward stop.
The EEC is computing this at all times so the yellow bug will move up/down as conditions change.
Note: you didn't mention aircraft type but my experience is 767 installation.
Last edited by Spanner Turner; 6th December 2017 at 14:49.
Reason: Added note