Originally Posted by
alfheimwanderer
Not quite. Confiding in Harry is more related to Shinji's feelings of alienation from / profound dissatisfaction with Britain, which he hasn't really talked about much. It also explains to him that Shinji - who used to be pretty big on his image - no longer cares, because he doesn't see a future there. What he says would be the truth - but it would not be the entire truth, as Shinji would omit things like the nature and fate of Fred's former familiar, Rachelle Lestrange's connection to the Eltnam, anything about Pansy other than the fact that she trained under Lockhart, and such.
Full Disclosure, on the other hand, is a much more complete explanation, focusing less on Shinji's feelings of isolation and more on answering Harry's questions, whatever they might be.