A few possibilities spring to mind. 1) Yuma's apple may be blocking something on the baby that Yubel finds terribly interesting. Apparently only the guys have noticed it. 2) Judai wishes he'd brought a neat gift like Yusei did. 3) Yuma just discovered his apple has a worm, and Kotori is pinching him for trying to give solid food to a newborn.
Well the way i see it is Astral and Yubel seem to be curious about the baby while Yugis crying because hes happy and Aki is trying to comfort Yugi. Anzu and Asuka are thinking how cute the baby is while Kotori is pinching Yuma for trying to feed the baby an apple, XD. Judai is annoyed because he has to wear a suit and nobody is paying attention to him while Yusei is looking at Yugi Jr and thinking about having one with Aki.
1) Yuma nicked an apple from Anzu's fruit basket, Kotori is giving Yuma what-for as punishment for theft, and Astral is wondering WTF Yuma and Kotori are doing (because Astral, while the Good Duelist between him and Yuma, is still infinitely curious outside of a duel). 2) Yubel is d'aww-ing over the baby just like Asuka is -- because let's face it, Little Baby Muto is just that adorable. 3) Judai has that expression because he just noticed Baby's First D-Wheel as made by Yusei. "Wait, he went and made a D-Wheel for the baby?!" . . . and Yusei is just either in Proud Uncle Mode or Anticipating Good Duelist Mode -- either one comes complete with 'this kid is gonna go far' expression-with-sparkle, though, so either way the result is the same.