Hi Maggie,
Unless there's some reason for excluding your images from being indexed, it might just help you gain some qualified and relevant traffic. This is especially true if you're running a shopping cart.
What does it mean to opt-in to enhanced image search?
If you choose to opt in to enhanced image search, Google may use tools such as Google
Image Labeler to associate the images included in your site with labels that will improve indexing and search quality of those images.
To opt in to enhanced image search:- Sign into Google webmaster tools with your Google Account.
- Click the URL for the site you want.
- Click Tools, and then click Enable enhanced image search.
Once you have opted in to enhanced image search, you can opt out at any time by returning to this page and clearing the checkbox.
Source: What does it mean to opt-in to enhanced image search?