Let us talk from the mathematical point of view. All of us have studied geometry and hence lets take the example of the triangle.
When you say I have 2 SAME triangle, it means that the are exactly the same. The length of all 3 sides are same, and the angles of all three sides are same as well.
When you say I have 2 SIMILAR triangle, it means that the are NOT exactly the same. The angles of all three sides are same, but they may or may not differ in their lengths.
So we can very well say that SAME triangles is a subset of SIMILAR triangles.
Applying the above logic,
I have the same phone. i.e. you have the same phone (say Nokia 1100) as the person next to you has(Nokia 1100).
I have a similar phone. i.e. you have the phone(say Nokia 1100) which is almost same as the person next to you has(Nokia 1201). Meaning the phone might be similar in looks or features but they are NOT exactly the same.