...
images should always be in landscape-format (preferrably with an aspect-ratio of 16:9) with a minimal resolution of 1920px width (or higher)
...
our recommended image-sources are as follows:
remember to mention the source of the picture when you use it eg: (Foto: unsplash.com)
...
example on how to select the appropriate image-format on unsplash.com:
...
