Lots of good answers here. Another minor one is Hollywood bias - older male actors got starring roles in romantic films. Random example, Cary Grant was 59 when he played the lead role in Charade opposite Audrey Hepburn who was 34.

Add to that the low quality of TV broadcasts, different styles of filing and lighting in movies, and less subtle use of makeup and people in film and TV from stuff from the 90s back have an other-world quality to them if you look back at that compared to the high definition world were in now. Even older magazines and pictures can be available at lower quality to us on the Internet than at the time, as we don't get to see the true originals but lower quality scans on the Internet compared to modern digital photographic.

It's amazing looking at old film from the 1800s that has been well kept or restored - not just people but the whole world actually looks real unlike what we're used to.

We're so used to looking at history in low definition or the artificiality of old fashioned TV/movie techniques and biases.