This chiasm tells us three things at the very least:
1. There is a right way and a wrong way to approach God. We cannot bring God down to us through the use of statues, icons, amulets, etc. He comes to us only in the time and place of His choosing and we have to meet Him there or not at all.
2. God's instructions (aka Torah) protect us from error. The Israelites made the calf because their hearts were unable to receive Torah directly. The stone tablets are an interim measure until we are able to receive the full Word of God as He intends. If we keep Torah faithfully, we will not resort to idolatry.
3. Shabbat, quite apart from the rest of Torah, also protects us. If we keep Shabbat in the way that God intends, we will be drawn closer to Him. Shabbat is as near God's presence is time as the Mishkan was in space.
Update: This chiasm is actually a little bit bigger than the image shows and spans six parshot.
- Exodus 24:15-25:2 (Mishpatim) - Glory of God, Moses, Sinai, fire, 40 days and nights on the mountain, in the sight of all the people
- Exodus 25-30 (Terumah-Tetsaveh) – Mishkan (right way)
- Exodus 31:12-17 (Ki Tisa) – Shabbat
- Exodus 31:18 (Ki Tisa) – Stone tablets
- Exodus 32 (Ki Tisa) – Golden calf (wrong way)
- Exodus 34 (Ki Tisa) – Stone tablets
- Exodus 35:1-3 (Vayakhel) – Shabbat
- Exodus 35:4-40:33 (Vayakhel-Pekudei) – Mishkan (right way)
- Exodus 40:34-38 (Pekudei) – Glory of God, cloud, Moses, Mishkan, fire, day and night in the wilderness journeys, in the sight of all the people
And here is a 4th lesson from this additional point: The close presence of God isn't cozy. Even Moses couldn't approach God in all His glory without being destroyed by it.