Double egg cups: twins

Are these for very hungry people? Or for very close relatives? The proved fact is that they are called 'twins'.

Unique details: 1) Aberdovey (Wales) souvenir egg cup, produced by Bukfast, a Devon company which made the same model also for other places [eggcup1823]; 2) Carlton Ware egg cup, marked "Carlton Ware, Gourmet, England", [eggcup1672]; 3) Irish egg cup [eggcup1591]; 4) bought in Brussels, 1988 [eggcup0821].
If you are looking for Carlton Ware pieces, remember to check our Carlton Ware egg cups post, where you can see for instance the Hovis Bakery egg cup or this Walking Ware egg cup.