Ever wondered why some of your Instagram videos tend to look blurry, while others are crisp and sharp? It’s because, on Instagram, the quality of your video apparently depends on how many views it’s getting. That’s according to a video AMA from Instagram head Adam Mosseri, in which he explained why some videos are lower-quality than others.

Here’s part of Mosseri’s explanation, from the video, which was reposted by a Threads user today:

In general, we want to show the highest-quality video we can … But if something isn’t watched for a long time — because the vast majority of views are in the beginning — we will move to a lower quality video. And then if it’s watched again a lot then we’ll re-render the higher quality video.

He continues, adding that the platform does this in order to “show people the highest-quality content we can.”

Instagram devotes more resources to videos from “creators who drive more views,” Mosseri wrote later in response to the Threads post containing the clip.

The shift in quality “isn’t huge,” Mosseri said in response to another Threads user, who’d asked if that approach disadvantaged smaller creators. That’s “the right concern,” he told them, but said people interact with videos based on its content, not its quality.

That’s consistent with how Meta has described its approach before. In 2021, the company projected it wouldn’t be able to keep up with the increasing number of videos uploaded to the platform. (Meta estimated last year that it served 4 billion video streams per day on Facebook.)

Meta wrote in a blog that in order to conserve computing resources for the relatively few, most watched videos, it gives fresh uploads the fastest, most basic encoding. After a video “gets sufficiently high watch time,” it receives a more robust encoding pass. Once it gets popular enough, Meta applies its most advanced (read: slowest, most computationally costly) processing to the video. The result, of course, is that the most popular creators tend to have the best-looking videos.