Facebook changes Primary Text visible to fewer lines and reduced media height for the photos and videos on Mobile News Feed.
Fewer lines of primary text on Mobile News Feed:
Currently, Facebook showing 7 lines of primary text to the Facebook post and ads on the mobile news feed. Starting August 19th, 2019 only 3 lines of primary text will be visible on Facebook mobile feed after that user need to click “See More” to view the entire content of the primary text.
Media height for photos and videos on Mobile News Feed:
For photos and videos, the media height will be reduced to a 4:5 aspect ratio from 2:3 aspect ratio. If the use post with media taller than 4:5 aspect ratio will not be shown on the Mobile News Feed.
Both these changes will be effective from August 19th, 2019 and applicable for both page posts and ads. These changes mainly to increase the ad effectiveness and improve the mobile experience for the user.
So the user needs to prioritize the main content of the post to appear within 3 lines of primary text on mobile or need to shorten the primary text for fully visible on the mobile. Otherwise, the mobile user needs to click “See More” to view the full content on your primary text of the post.