While posts that are old enough show the hour and minute they are from, it is, as far as I know, impossible to get these for recent posts.
It is possible to see the proper timestamp for any post - but it is a bit of a faff. As it requires several steps to see the timestamp for each post and isn't a simple matter of hovering over the time, this is really a workaround.
You can go to the timeline (an experimental feature of the site) of any post by copying the URL of the "edit" link at the bottom, and changing the /edit
to /timeline
.
For your question, that means changing {MSE}/posts/327106/edit to {MSE}/posts/327106/timeline. The page then shows an itemised list of events that have happened to it (reviews, comments, etc.). The event at the bottom is when it was created - in this case, when you asked the question.

This shows times as they appear in the normal view, (e.g. me answering your question says "4 mins ago"). If you want more precision than just MMM d ['yy] at H:mm
then click (or tap) the "toggle format" link near the top. That will change the times from the short date and time format to the ISO 8601 date and time format (note that daily summaries, which are provided at the end of the day, never have the time specified):

As I said, though, this is a bit of a faff - as a regular mobile user it's annoying to have to do this every time I want to see the exact timestamp for a post.