why SnapshotThreshold smalll than trailinglogs?

[zdyj3170101136]

SnapshotThreshold default condig is 8192.

trailinglogs default config is 10240.

if we have 9000 logs now, we will try make snapshot, and beacusr of 9000 < 10240,we will stop make a snapshot.

if we have 10241 logs now, we will try make snapshot, and because 10241 - 10240, we will make snapshot with 1 logs.

so why SnapshotThreshold smalll than trailinglogs?