Frankly anytime i see Jimmy Stewart kissing somebody in a movie it looks violent. We just rewatched this movie with the grandkids and this is not the only time he grabs and kisses her violently. Personally i think it’s a combination of bad acting and what was considered a manly display of emotion at these time.
Meanwhile my partner and i have found it impossible to watch the old classics anymore because of the rampant sexism racism and lots of other isms. Sad loss but otoh it’s good to see that society really has changed for the better in some ways