They appear to be scrolling through a single social media feed. This operation is likely what those social media "boosting" services are doing, where they'll bring a ton of new traffic to your profile to try to goad the algorithm into sending real users your way.
There are a ton of things you can do with a keyboard natively on Android. I would imagine these use that plus a bit of software to emulate "real" movements, like the flicking down to scroll
All of my Twitter followers are thot-bots. I don't even get the good ones that have pictures of cats in their bio. Just poorly photoshopped Kim Kardashian body swaps.
Since their usage is probably forbidden my the TOS of the platforms they use, and the platforms will try to detect this kind of usage and ban users, I would assume that the closer they appear like natural usage, the more effective they are.
Running these apps on a emulator and using VPNs etc. will probably be a red flag.