Physical beauty- Objective or subjective? Cultural or universal?

Indeed!

I hope to look as good when I'm 60. Just need the hair to grey up a little faster

 

Compete how? Can they get a man to their bed for a quickie nooner? No doubt, but what then?https://www.youtube.com/watch?v=b53EbA1NBRk
Also, these older ladies you're showing us are the exceptions - not the rule. We're talking in general terms not specific terms.
Objective beauty - If we took only headshots of 100 women, and showed them to 100 men from around the world, we could arrive at a general consensus on the majority, and I'm guessing 95%.
To say that beauty is purely subjective is like saying that gay men can't be judges in a beauty contest, which is of course BS.
Attraction - this is where the subjective part comes in, IMO. But there is also the subconscious attraction to traits already mentioned.

 

Romantic attraction that is. Which is not really subjective, but more of a totally random phenomena.