Tbh I really like the idea of the Lukas family looking unusually young because of how much time they spend indoors/how unsocial and inexpressive they are, so when they die, they always look like they were taken too soon no matter how old they are. Bonus: the Lukas’ rarely, if ever reach life expectancy due to heart issues running in the family. 

If they made a family portrait, it’d just be a bunch of pale, grim faces, with no laugh lines and no other signs of a well-lived life. Extremely unsettling to look at. And it would be 100% a cursed painting lmao.