There a site which says on verbal periphrasis:
sentirse + p.p. means "to have been “somethinged” - passive"
I am not sure I fully understand that given they offer no examples to illustrate the meaning. Google search didn't help much either. My personal understanding says it could translate into something like to feel done:
Me siento cansado.
I feel tired.
This, of course doesn't seem to be anything like what the website in question says. Is there some nuance I am missing out on? Also, should the past participle in this construct inflect with the object or subject, if at all?