The korban omer parallels to the mann in that they both force one to recognize the bracha that Hashem is giving. The blessing He gives is not in an obvious quantitative way, rather, it is a bracha that comes modestly. When we doubt that Hashem will take care of us, and give bracha, then He gives large quantities in an obvious manner. The ideal, though, is to recognize the quality within the bracha Hashem gives. We must recognize He takes care of every detail, and not get stuck worrying about the comfort of the quantity that we see with our bare eyes.