Don't look at this from the perspective of why this was so lousy. Look at it from the perspective why this is so good.
I thought Earth-observing satellites need to be extremely stable to provide a clear picture.
This is extremely stable. Look at how clear each frame is.
but the video seems to suggest that the satellite is making lots of small corrections ...
This is very likely the satellites attitude control. If the satellite is not controlled it will not just remain in its current orientation but at least rotate slowly. Maybe the solar radiation pressure will lead to a stable orientation after some time (Kepler used something similar and the new JWST has a momentum flap to keep its attitude stable) or maybe it ...
The Symphonie satellites A and B were the first communications satellites built by France and Germany (and the first to use three-axis stabilization in geostationary orbit with a bipropellant propulsion system) to provide geostationary orbit injection and station-keeping during their operational lifetime
Symphonie-A was launched from the ...
NASA published an extensive answer to this question on their blog today. Some key points as to why no cameras were added:
You wouldn't actually be able to see anything useful: a wide-angle camera would not provide enough detail, and you would need so many narrow-angle to get enough details for them to be useful, that it would be too complex to be worth the ...
mentions several reasons for not having a camera:
would need several cameras at several locations
would need artificial light
should be constructed from scratch to resist the low temperature on the dark side
In case of failures could create unwanted debris
keep load to a minimum