That neck heel looks just the way it should on a Tele. The simplest way to fix the problem is the way TD suggests. However, you may want to check to see whether the pickguard looks more like the pocket or more like the neck.
The other way to do it would be to use the neck to mark in pencil how the end of the neck pocket should look, and then modify the corners of the pocket with a rotary tool.
I try to modify the neck pocket rather than the neck when possible. My logic is this: You see how the pickguard fits. You see the ends of the neck. But you don't really see the end of the pocket itself because the pickguard covers it...so if I slip with my rotary tool, no one but me will know ;-)
Also, if you ever want to swap out the new neck may fit without sanding... Having said that, I have, personally never had to swap out a neck...and I have definitely used the TD approach particularly when I am not using a pickguard ;-)