Execution Plan and Results of Aggregate Concatenation Queries Depend U

I was reading the blog of Ward Pond, and I came across another note of Microsoft. I really found it very interesting. The given explanation was very simple; however, I would like to rewrite it again. Let us execute the following script. This script inserts two values ‘A’ and ‘B’ in the table and outputs a simple code to concatenate each other to produce the result ‘AB’.