Beaver teeth need worn. Like rat teeth , breaking enamel away on an edge to wear them sharp. But very importantly to wear them.
They just keep growing.
A tooth can be exposed over an inch but be a three inch or longer tooth.
Unworn examples are not pretty.
Your beaver has worked the easy and choice stuff.
risking exposure on land where channels aren't dug easy enough to be worthwhile. Getting farther from water to cut bark supporting limbs . Vital for thier inner bark...
Tree drops towards water it's a win. Away from water , bummer. But still ,limbs to cut.
It hints it want to parallel water. But the wind will get a vote if the trunk gets weakened more.
Beaver has found the harder wood towards the heart. It can start from there and work around now. Depending on why it's cutting. The shoots at base of trunk are gone so were likely snacked on. If not secured in the river bottom for winter larder. Depends on how the groceries been! (Which again look thin by the size of the pictured target.).