These images are freely-usable ones from [Unsplash](https://unsplash.com/). - https://unsplash.com/photos/rDEOVtE7vOs - https://unsplash.com/photos/et_78QkMMQs - https://unsplash.com/photos/ILip77SbmOE - https://unsplash.com/photos/95UF6LXe-Lo