I've been a fan of Portia's since Nick Freno:Licensed Teacher (anyone remember that show, lol?) and I love her in this role.
She does look significantly different than she did last season. At first I think it was just the tan i was noticing, but now i think it's the thinness. She definitely looked better last season, she's very scrawny now.
And as for her role on the show? Come on! No member of the Bluth family is expendable, they all make the show the way it is. And I think in one of the featurettes on the DVDs, Mitch Hurwitz says that the great thing about Portia is that she plays the Lindsay character like as a miniature Lucille. SHe's like a younger shadow to the Lucille character.
We may pick on each other, get into little scrapes, call each other names and occasionally steal from each other, but that’s because we're family.