Basically you can drag on the scrolling bar thing and move around. I’m so dumb so this probably makes no sense here’s a video.
I am pretty sure that is intended to move around byte faster or say for instance in certain category when you leave and come back you will see the same bytes at the top so you might wanna see something new and wanna skip the old ones faster so you use the bar. Or if you wanna get back to the top since there is no place to implement a back to the top button.
ohhh haha, just thought it was unusual for a social media app but it makes sense now tbh