Page.Files

to get a page's subpage' info:

{{ page.files}} 

retrieve properties of the first image by converting the map to a list
The list contains a key and value argument for each map element, so to access the file properties you need to add "value"

{{var myList = map.keyvalues(page.files);
myList[0].value;
}}

retrieve some properties of the first image

{{var myList = map.keyvalues(page.files);
myList[0].value.description;<br/>
myList[0].value.date;<br/>
myList[0].value.author.name;<br/>

web.image(myList[0].value.uri);<br/>
}}