Besides all the official gyms, there are also unofficial gyms. After beating those, you will also receive a badge. Therefore, I think that those badges were obtained in one or more of the unofficial gyms. The one just right from the top left looks somewhat like the Coal Badge from Sinnoh though.
Unofficial Gyms in the anime:
- A.J.'s Gym
- Fighting Spirit Gym
- Kaz Gym
... and many more.
There were 15 gyms in the Kanto region, that is one gym for every type, minus Dark and Steel types. This means they were not featured in the anime/game to prevent confusion, but still are considered official gym's.
Anyways it would make sense that Ash only went for eight badges compared to a possible 15. Most of his badges in the first season were given to him without even finishing his gym leader battles plus the games only featured eight gyms so then changing it to a higher number in the anime might have been confusing for fans. Source