Offering jewellery on Buddha images is a method towards accumulating merit. It is also a method to create the causes for wealth and money, and to be beautiful from inside out through transformation of negative qualities to the selfless wish to benefit others.
With sincere intentions, one can offer jewellery on Buddha images, thereby creating the causes mentioned, a body beautiful to look at, and charisma to inspire others positively in future lives and in this life.
It is also a wish to achieve the Buddha body that is healthy and strong, and thrives on benefiting others. Last of all, making offerings towards a particular Buddha creates connection of blessings and protection with a specific Buddha.