Originally Posted by
Abbey Road
I don't believe those momentary tiny 'flashes' are sparks. They look more like something in the air (rain drops?), immediately ahead of the engine intake, being illuminated by a nearby light, likely the starboard landing light in the wing root.
Certainly looks like something being picked up at the start of the roll. Now, seeing sparks suddenly coming out the other end of a gas turbine can lead to some "entertainment" as I witnessed once!

Not a GE90 ...... but the bang when it all gave way was loud enough.