I'll say simply- this is very Apples and Oranges and there's a lot of factors in play.
Firstly, this is Television- as a result, a pinch, cup or gritting lorries worth of salt should be taken with whatever is seen. Sure, sometimes it's sincere, but folks- this isn't (sadly) a world where nothing but facts is shown because who wants facts when they can sit and watch fiction that's more exciting and generates higher views?
Secondly- who's to argue what the "norm" is in this situation? Some families simply are that close, we impose meaning, intent and our own values on others actions in what can frequently be called plain prejudicial. In some cultures and countries, it's quite "normal", regardless of gender, to kiss one another on the cheek as a greeting, in others, it's "normal" to shake hands.
Without actually having some solid background on them or knowing them as people, it's not fair or easy to judge precisely what the intention or meaning is behind any of this is. For them, this could be "normal", it could be it's manipulated for TV to appear semi-controversial.
I've seen friends greet each other with kisses on the lips, cheek, hugs, shakes of a hand and family members of all ages say they love one another- regardless of if they're speaking to their children or extended family.
Perhaps I'm open-minded, or too broad with my views not to judge on account of these actions and not reflect on it as somehow being a window into how they are as people or what relationship is behind it.