there are 2 things that bothers me a little, but one of them at least may be simply a matter of taste in the browser use.
firstly, when you click on an attached image it now gets displayed in the pop up, which is cool, but clicking on it it gets spawned in another page (or tab): could it be made as for HOL which closes the popup wherever on the image you click? if you want to open the image in a tab, you can always use the middle click of the mouse.
secondly the emboldened number of the notifications goes often unnoticed by me. can it be made in a different colour?
both are just minor things, if you / majority prefer them as they are it's ok