Based on Faker for PHP, the Image provider get images from lorem pixel or unplash to dowload images by categories.

Other alternative is place kitten but only for cats photos.

Exemple img URL:
Lorem Pixel: http://lorempixel.com/800/600/
Unplash: https://source.unsplash.com/1600x900/?nature,water

Faker PHP repository(use lorem pixel): https://github.com/fzaninotto/Faker/blob/master/src/Faker/Provider/Image.php
Faker JS repository (use unplash): https://github.com/Marak/faker.js/blob/master/lib/image.js