Haitian Vodou bottles, also known as boutey lwa or spirit bottles, are significant ceremonial objects used in Vodou rituals and serve as devotional pieces. 
Appearance
Decorated with Beads and Sequins: These bottles are often elaborately decorated by hand with colorful sequins and glass beads sewn onto fabric covering the bottle. The shimmering quality of the beads and sequins are believed to attract spirits and invite them to Vodou worship.
Vévé Designs: The decorations often feature intricate vevé designs. Veves are symbols representing specific spirits (lwa) in Vodou, marking the point at which the lwa can enter the human world.
Variety of Shapes and Sizes: Vodou bottles come in various shapes and sizes, sometimes repurposing old rum bottles or featuring elongated rounded shapes with long necks, or cylindrical shapes with rounded shoulders and no neck. 
Purpose and Use
Honoring Spirits: They function as devotional altar pieces to honor specific lwa, spirits, or ancestors.
Invoking Spirits: During ceremonies, the bottles can be filled with offerings such as water, kleren (Haitian raw sugar cane rum), or herbal remedies to invoke the immense power of the lwa.
Spiritual Art: They are also appreciated as unique pieces of spiritual art and can be displayed in homes. 
Symbolism
Vévé Designs: Each vevé design is associated with a specific lwa and their attributes. For instance, the Erzulie Freda vevé, often seen on bottles, represents the lwa of love, beauty, and compassion.
Objects Inside: Some Vodou bottles are filled with symbolic items such as roots, herbs, or other materials believed to enhance their spiritual connection and purpose. 
It is important to remember that Vodou bottles are sacred and hold deep religious significance within the Vodou faith.