Just some nitpicks on the popup itself:
- The callout has an acute angle on the left side which is distracting, a symmetrical callout would look cleaner
- The callout is a little larger than seems necessary
- The popup has a horizontally biased border radius (is this on purpose?)
- The border radius on the popup doesn't mesh well with other graphical elements in the MediaWiki UI, or with the tool itself
- The popup has too small of margins given it's large border radius - they are probably fine with a smaller border radius
This post was posted by Trevor Parscal (WMF), but signed as Trevor Parscal.