That not only was a great question you posed, but a fantastic GIF of the moon going through diurnal libration as Bill and Curt described so succinctly. The only bad part about that GIF is it's giving me some really painful flashbacks of some awful disco parties I went to in the '70s! lol.
If I may add one more comment about Diurnal Libration. Unlike Longitudinal and Latitudinal Libration, which as stated is primarily a function of a combination of the eccentricity and elliptical nature of the moon's orbit, Diurnal Libration is greatly affected by WHERE you are on earth.
Your calculation of 4,000 miles for the transverse distance an observer travelled during the 4 hours of the lunar eclipse, resulting in an approximate 1 degree of parallax, would only be experienced at the equator. As you travel farther away from the equator, the transverse distance (or baseline) used for the parallax calculation becomes shorter and shorter, until it's the size of a gnat's brain at the poles ( and mine sometimes according to my wife!!!). To calculate the baseline for any given latitude, multiply the 4,000 mile radius of the Earth by the sine of the complement of your latitude.
As an example, where you are in Tempe is about 33 degrees latitude, so sin57*4,000 = 3,355 miles. Since the length of the baseline is directly proportional to the observed parallax, the approximate 1 degree of observed lunar parallax at the equator would only be about .8 degrees. Where I am, about half an hour north of San Francisco, its about 3/4 of a degree, and in Anchorage it's a tiny bit less than half a degree.
As a final thought, and I'd enjoy hearing feedback from any or all of you. I thought I had read somewhere years ago that a small portion of libration is also due to the uneven gravitational attraction the earth has on the moon due to the earth's varying density, thus slightly changing the orbital speed of the moon. While this definitely affects the orbital speed (albeit it slightly) of something like the ISS, I don't think the libration of something as far away as the moon would be observable.