syntax - Nominal and Adjectival

1. The fact that you are here is an indication of your good intentions

My analysis of the clause in bold is Noun-clause/Adjectival/Post-nominal modifier.

However, my teacher's answer is slightly different. He said that the clause in bold is Noun-clause/Nominal/Post-nominal modifier

2. The dress that Melissa is wearing was designed in Paris.

However, in the sentence above, my teacher said that the clause in bold is Noun-clause/Adjectival/Post-nominal modifier

My questions are:
What is the difference between the Noun-clause in the first sentence and the second sentence?
Both of them modify the preceding noun, so what makes the first one "Nominal"?