I can't find a trailer, but here's one scene:
Slant Magazine says,
Gertrud is a film that is as richly mysterious and inscrutable as it is earthy and wry. It’s this frequently unrecognized artistic relevance that continues to inspire debates, wild interpretations and, yes, frustrated indifference. This is not to say that debate and varied interpretation are the hallmarks of a work of great cinema, but rather evidence of a film that audiences still find vital and alive.The New York Times found it dated even at its premier. FilmReference.com says, "She knows that her demands on life cannot be fulfilled, so she chooses to live in accordance with her inner demands. ... This is not a naturalistic portrayal, but a tragic one —Gertrud is bound for defeat."
Rotten Tomatoes has a critics score of 79%.