how to interpret group significance plot

i have metter...
i can`t interpret group significance plot.

  1. what is more close to group 1?...

    • group 2?? or group 3???
  2. why 1 to 1 distance is highest among 3 groups??

    • i think 1 to 1 distance should be lowest in among 3 groups!


To 1: 2 and then 3
To 2: 2 and then 3
To 3: 3 and then 2

It's logical but I guess that group number 1 is scattered all across the PCoA plot, meanwhile groups 2 and 3 are more closely plotted and centered. So due to high distribution within the 1 group inner distances are higher compared to more centered samples from groups 3 and 2. At the same time, samples from groups 2 and 3 may be closer to the center, so distances from them to samples from group 1 are shorter.
For example, linear representation: