Hook: Floor Large (Purple Square)The Zakuulan Arbor Arrangement decoration fits into a large purple square floor hook.
Hook: Centerpiece (Giant Purple Square)The Zakuulan Arbor Arrangement decoration fits into a giant purple square floor hook with beams of light.
How to Get a Zakuulan Arbor Arrangement Decoration
Cartel Pack Decorations
The Zakuulan Arbor Arrangement decoration can be dropped from Eternal Command Packs, which were released on the Cartel Market and bought with Cartel Coins. Cartel Packs, including the Eternal Command Pack, include a random selection of items from the Eternal Command collection of items. You aren't guaranteed to get a Zakuulan Arbor Arrangement decoration from a Eternal Command Pack, but it is one of the few ways to get a Zakuulan Arbor Arrangement deco apart from buying it on the GTN from another player.
If you're looking to get a Zakuulan Arbor Arrangement, the easiest way to get it is to head to the Galactic Trade Network (GTN) in SWTOR and buy it with credits from another player. If it's very rare and not available on the Cartel Market, you could try buying from the GTN and hope you get it.