It is easy to understand why the developers of this extension designed it with emphasis on numbers. But one should consider that 99% of users aren't technically inclined.
Instead of focusing on those numbers it would be more useful to hide these as advanced options, and make it possible for the average user to understand the impact of the page. For example, some actionable data might be recommended sizes:
| Data | Cur tot size | Recom. size | Cur no. | Recom. No. | Mobile load times (200KB/s) |
|---|---|---|---|---|---|
| Images | 500KB | <300KB | 60 | < 50 | 30s |
| Markup (links , tags) | 700 | <200 | 2s | ||
| Other (CSS, js, other) | 100KB | <50KB | 10s | ||
| Total | 600KB | <350KB | <200 | 42s |
These are just made up numbers that hopefully make it is easy to get the general idea. The difference is that this is something that users can see and do something about (reduce images, reduce markup) without understanding core principles about website design or performance or worrying too much about things they can't do anything about (e.g. CSS, JS, etc).
Pie charts and colors for performance status, might also be meaningful way to indicate general page status (e.g. RED - very bad performance, green - fine), although people can just implement that using userscripts.