The most obvious difference in Book 4 itself is that Ithaca is under seige by a group of invaders - pretending to be "suitors" - and that Sparta is peaceful and under the control of its leader. Meneleaus is clearly in charge of his dominion. He welcomes his guest, serves a nice meal, and shows his power as a king, a father, and a husband.
Ithaca, at the same moment, is at the mercy of a band of usupers. The suitors have come uninvited, have taken over the palace, have helped themselves to food and more, and have shown complete disrespect for Odysseus and his family. Penelope is barely holding things together through her manipulation of the situation and because Odysseus' death has not been confirmed. Telemachus has had to flee in disguise to seek help.
Overall, though, the description of Ithaca and the history of Sparta show two very different lands. Ithaca has been a peaceful farming community, while Sparta has always been a militaristic city.