A couple things:
1 - It may come apart but doesn't really look like it given the paint.
2 - Those seatstay look like carbon fiber and not steel like the rest of the frame. That end is probably epoxied to the dropout that is brazed into the chainstay and would have some adjustability (See 3 below).
3 - There are dropouts with pivots as shown in the picture that provide adjustability for the angle of the seatstay attachment point. Dropouts with fixed angles between the chainstay and seatstay attachment points usually come in only a couple angle configurations. For small frames this is a problem.