Author has an interesting pair of comments on Japanese cultural aspects of Shirobako over on ani-nouto. He appears surprised that anyone would want him to blog about them, and seems to think they are obvious, but I can assure him, and you, that they are anything but.
The first is the phrase “make a living at X”, which in Japanese comes out as “eat by doing X”. Crunchyroll has the direct translation, but the US release blu-ray uses the English term.
The comment-worthy aspect of this is the dropping-the-donut scene where the rookie loses it, and old-hand Yasuhara-san catches and eats it.
The other point was a deconstruction of the 3rd Flying Girls Squadron author comments about the manga representing his inner turmoil. The discussion is more complex and nuanced than the “making a living” comment, so I’ll just point you at the original page.
The point of all this is that to understand socially-based content from a society as different as that of Japan requires multiple translations, and expert commentary. I noticed the frequent references to eating, but didn’t really map them to making a living, and even when I did, I didn’t pick up on the other aspects. That’s what makes watching anime so much fun, and so confusing.