Roses generally refer to the flowers, their red colour and to a pleasant fragrance.
GARLAND OF ROSES is the etymological translation of Rosary (lat. rosarium), a catholic object used for praying in the honour of the Virgin Marie.
This garland of roses represents like an opposite to roses. It is still an object in the shape of a rosary but white, immaculate, a ghost with clinging smell. Instead of the flower's perfume, we smell something that reminds us a past memory, a smell that haunts grand-mothers wardrobes:
Naphthalene.
The Rosary, like naphthalene, belongs to the past. It is therefore presented in a glass container, like a relic, something holy but that is no longer in use.