It is a subconscious level ad for the utility/value of the platform. You don’t need to be overt about the screenshot containing Lemmy by name. Any subtle details are all that is needed. This is all it takes to attract the most valuable people; simply show them that they are missing out on something useful. It is effective psy ops.
I asked on my school’s subreddit if there was a Lemmy community. Got like 4 replies, all basically variations of “never heard of it” and one person who freaked the hell out about how I, personally, was the ruination of reddit for asking this. Lmao
The one person freaking out was prolly a bot programmed to reply to lemmy posts
Seems like the average Reddit experience ha ha