Tiling on small screens does not quarter tile first

14" Galago galp2 (3200x1800 scaled 200%)

Pop 21.04

```
pop-shell:
Installed: 1.1.0~1628527572~21.10~3eda9bb
Candidate: 1.1.0~1628527572~21.10~3eda9bb
 ```
 
 (Sorry for the webm zip attachment. Peek isn't behaving)
[tiling-video.zip](https://github.com/pop-os/shell/files/6976623/tiling-video.zip)
