This means that it must be a hardcoded value. Instead, it should adhere to the system preferences. I consider this an accessibility issue.
In fact, that image shows that it doesn't adhere to any of the few preferences available, but that's probably best kept to a different issue considering that it's a DE-specific preference adherence rather than this very generic issue, despite being as much an accessibility issue as this.
Your system information
Steam Logs
logs.tar.gz
Please describe your issue in as much detail as possible
The “Default” size preference is too large for my system by one or two pts:
This means that it must be a hardcoded value. Instead, it should adhere to the system preferences. I consider this an accessibility issue.
In fact, that image shows that it doesn't adhere to any of the few preferences available, but that's probably best kept to a different issue considering that it's a DE-specific preference adherence rather than this very generic issue, despite being as much an accessibility issue as this.
Steps for reproducing this issue
Notice the difference between the GUI size everywhere except the chat itself and the chat?