They are both the same vid. One is the actual news helo footage, albeit stabilized, and cut at a critical time, which is, in itself, very unusual.
The grainy vid is from VHS playback, recorded onto camera, for the PC.
The 2nd vid shows eyewitness, who said on live TV that cruise missile hit pentagon.
Remember, this was broadcast live, and hundreds recorded it onto VHS.
https://www.youtube.com/watch?v=uhkQDXlSdMY&t=256s