Oil painting work station

With the work station almost completed, all that was left to do was build a drawer.
Using 3/4" x 3 1/2" boards I made a 14"x 23 3/4"drawer.
I'm not sure what kind of a joint this is, but I made a mistake and cut something wrong....And this is how I fixed it......!
I'm sure if its an inferior joint, my brother will let me know!!