@BowlOfRed's comment nailed it.
I'd thought about making an optical flow version but time does not allow, so I've just used screenshots and imageio found here.
It looks like the spacecraft was overhead, and in fact did move many degrees (as seen from the ground) during the 17 second video of Buenos Aires.
They are clearly remapping frame-by-frame using some reference in the image, and not the calculated surface of the Earth. If you look at the shore of the river which should be relatively constant elevation, the shore oscillates in areas that contain tall buildings, and in the opposite direction than the tops of the buildings. In areas with no tall structures such as the extreme right of the video frame, the shore is motionless.
See this GIF for that: https://i.stack.imgur.com/vkpGw.gif
This suggests that they are nulling something like the average motion in each region of the image, rather than using a calculated ground.
The best place to look to see what's happening is the pair of bridges at the top left corner of the first GIF. The tall buildings at the bottom right corner of the second GIF are also a giveaway.
Sorry for the vertigo-inducing GIFs!
below x2: The pair of (very tall) bridges in the first GIF, screen shot from Google Maps.