using [] to group multiple images within a node with JSON

Im trying to get my json output to use square brackets [] to group multiple images in a node like this:

"name" : "Fifth Avenue",
"images" : [
"/images/fifthavenue_hero.jpg",
"/images/fifthavenue_gallery_image4.jpg",
],
},{

instead of this which the viewe is outputting:

"name": "Fifth Avenue",
"images": "/images-locations/cheddar.jpg?,
/images-locations/cheddar2.jpg",

},{

Is there a way or a work around to achieve this please? As a third party app needs this configuration.
Thanks