[nine_k]

There is a large, very visible shining crack on the lower left. I assume it's the source of the flare.

I suspect it's not very easy to see a flare when it's directed right at you. I assume the video is from a telescope close to Earth, so it's not showing us the ejection from a side, which would make it more visible.

[voxelghost]

SDO is in a circular, geosynchronous orbit at an altitude of 35,789 km (22,238 mi), at 102° West longitude, inclined at 28.5° [ so says wikipedia]

The image over at spaceweather helps identify the location of the flare https://www.spaceweather.gov/news/region-3341-produces-x11-f...