What did my plane/pilot do departing YYZ last week? Felt like it “charged up” while stationary on the runway

During engine operations on the ground while in icing conditions, and with OAT at +3°C (37°F) or below, ice accretion may affect the engine fan blades, spinner, or stators of the low pressure compressor. The quantity of ice accretion depends on the time during which the engine is running on the ground in the above mentioned icing conditions. On the Airbus A330, we routinely perform the "Engine Ice Shedding on Ground" procedure when the above icing criteria are met. Under circumstances where there is no presence of freezing fog, we simply apply the "Fan De-Icing" procedure, which is most common. We then communicate that information with to tower frequency (before lining up) that a "run up" will be required, meaning we'll be staying on the runway for longer than expected. After receiving our run up approval and takeoff clearance, the PF (Pilot Flying) applies sufficient manual braking to remain static on the runway centerline, then moves the thrust levers appropriately in order to achieve 50% N1. The PM (Pilot Monitoring) then starts the chronograph for 10 seconds. During that time, the PM also observes the three (3) engine vibration indications on the EWD (Engine Warning Display), which will be indicative of any accumulation of ice accretion remaining on critical engine components. If all parameters are within normal operating limits, he communicates that the values are stable to the PF and that the 10 seconds is up. PF then applies calculated takeoff thrust. The rest is Standard Operating Procedures. In your case, however, it looks like the Flight Crew may have used "PROC B": To be used when the OAT is -20°C < OAT ≤ -7°C and freezing fog is present. This calls for 70% N1 for 50 seconds. Keep in mind that these values apply to the A330 equipped with the Rolls Royce Trent 772-B, not the A321 - But the purpose remains unchanged. I hope that I was able to cater to your questions and concerns. Perfectly normal and routine - Especially in the colder months. Happy flying!