If a post starts with a photo, the image description is pulled as the excerpt.
NZ:
https://www.greenpeace.org/new-zealand/story/these-banks-are-still-funding-dangerous-oil-pipelines-heres-how-you-can-stop-them/
Canada:
https://www.greenpeace.org/canada/en/issues/live-sustainably/2344/g7-charter-wont-effectively-tackle-plastic-pollution-but-canada-can-still-act/