You might try calling the store manager to make an appointment to come in and meet them. One of the members of the Florida Society of Goldsmiths did this to the Dali Museum, then offered to send photos. Once they saw the photos, she went in person with the work, which they now carry.
Do your pieces open? I would recommend a composite photo showing the movement, if it converts, etc. Your composition is lovely, but most pieces that win art shows or attract buyers have a memorable component about them. Tell the story too!