The IMDB blurb talks of these being Vienna performances from the early 1970s. Yes...and no. The London Symphony Orchestra performs No.2 in Ely Cathedral, and the Israel Philharmonic are also in play for Das Lied Von Der Erde. The amazing performance of No.9 is given by the Vienna Philharmonic but in Berlin's Philharmonie, not in Vienna. The No.8 is, if memory serves, performed in Vienna but not at the Musikverein.
Bernstein was a very theatrical presence on the rostrum, determined to live the musical performance as extrovertly as possible. So he smiles, he laughs, he sings, he cries, he jumps, he shakes and rattles and rolls, and at times he looks like he has 1000 volts running through his baton. The Vienna Phil. Ought to have been right at home with this music but it took Bernstein from New York to teach it them. When he later went to the Berlin Philharmonic to give charity concerts of No.9 he found the orchestra hadn't touched the music for a decade or so. Bernstein was a great musical pedagogue and so if you are new to Mahler you could hardly do better than watch these films of a legendary proselytizer at the peak of his powers.