Different sub-headings - is there a reason that I am missing?

Question

https://progress.lawlessfrench.com/my-languages/french/review/4711/3669698https://progress.lawlessfrench.com/my-languages/french/review/4712/3669698I am unsure why «pour avoir (past participle)» is sub-headed 'simple expression' and «pour être (past participle)» is sub-headed "complex expression". Is it because the latter lesson also includes reflexives, or am I missing some other complexity with «être»? The lessons and phrases seem otherwise essentially identical, using avoir or être as required by the verb in infinitif passé form.

Accepted Answer

Hi Maarten, 
You got it right, the added complexity comes from the rules of agreements with être ( with the subject, so there will be many more of them) and the additional reflexive verbs with additional pronouns. 
Bonne Continuation!