Legends of images associated to your products are used by search engines to index your website. When it comes to SEO, it is therefore important to optimize image indexing by improving the legends.
Technically, it's a HTML tag, the ALT tag. It is used to improve your whole website indexing because you can integrate additional keywords that will be read by search engines. Although there is no need to over do it :)
The ALT tag (or ALTernative text) is a text that will be displayed in a web browser if the image itself cannot be displayed (browser incompatibility for example), or if the visitor mouses over the image.
It is therefore advised to add main keywords in a simple sentence that would includes page information and what the image represents.
To quickly modify image legends in Store Commander, open up the Images panel (Properties left handside column), and double click the cell to edit, once a product is selected beforehand.
In the case where you want to use the product name to be the image legend, use the corresponding option located on the Image toolbar.
Click this icon once you have selected the image(s) and the legend will be automatically added using the product name.
Of course, apply this action to multiple product images :)
Select the products > select the images > apply the image legends.