Fixes profile full-image view bug

The bug occurred when you're viewing an image full-view, then you either:
1) Switch to another conversation and return, or
2) Re-download the profile.
When you did that, the profile displayed nothing at all (trying to view image in full, but displays nothing instead).
what's up here? why did you have to change to an element binding? does `ShowNotifications` not properly call `PropertyChanged`?