What is the meaning of ta-form + 上で in this context?


> このうち、これまでに５回、パラリンピックに出場した競泳の成田真由美選手は、左手が不自由で、ふだんからエスカレーターの右側につかまって乗っていることを
> **紹介したうえで**
> 「意識を変えることに費用はかかりません。障害のある人の立場にたって考えてほしい」と呼びかけました。([article](https://www3.nhk.or.jp/news/html/20180623/k10011492721000.html?utm_int=news-
> life_contents_list-items_006))

According to the answers of this
[question](https://japanese.stackexchange.com/questions/15190/meaning-
of-%E9%81%8E%E5%8E%BB%E5%BD%A2%E3%81%AE%E5%8B%95%E8%A9%9E-%EF%BC%8B-%E4%B8%8A%E3%81%86%E3%81%88%E3%81%A7),
"ta-form + 上で" means that the second action is performed based on the result
of the first action.

If the writer had used てから, it would have meant : doing the 紹介 and then the
呼びかけ (without telling anything about the relation between them except that 紹介
is made before the 呼びかけ)

But the author uses 紹介した上で, so it means(according to the stack exchange post I
linked before) that the result of 紹介する is used to do the second action (呼びかける)

I don't understand what is the "result" of 紹介 and how this result is used in
the 呼びかける.

According to me, the result of a presentation is the reaction of the public,
so 呼びかける should be made according to the reaction of the public but it sounds
odd because since the 呼びかけ tries to raise the awareness and convince the
public,it would mean that the reaction of the public was negative.

I don't think it's the correct interpretation so my very question is:

**" ta-form + 上で" means that the second action is performed based on the
result of the first action. In the context of this article, what is the
"result" of 紹介 and how is this result used in the 呼びかける ?**




As you have pointed out, understanding this ta-form + 上で expression is
dependent on understanding what "result" is being referred to.  
The result of 左手が不自由で、ふだんからエスカレーターの右側につかまって乗っていることを紹介する is that people are now
**aware of the reason** she and others in similar situations have to be on one
side of the escalator. So now that that reason has been announced publicly,
she is asking that people be more aware of such situations, be considerate,
etc.




As you have pointed out, understanding this ta-form + 上で expression is
dependent on understanding what "result" is being referred to.  
The result of 左手が不自由で、ふだんからエスカレーターの右側につかまって乗っていることを紹介する is that people are now
**aware of the reason** she and others in similar situations have to be on one
side of the escalator. So now that that reason has been announced publicly,
she is asking that people be more aware of such situations, be considerate,
etc.

