how do you unhide tagged photos on facebook

It's probably just because you need to adjust your settings for the Photos app. Here's how ya do it:

1) Click the "Applications" link at the left.
2) Scroll down to the "Photos" app. Look to the right of it. There should be a link that says "Edit Settings." Click that.
3) In the pop-up, make sure the box that's second from the bottom marked "Add a link below the profile picture to any profile" is CHECKED.
4) Click the blue Save Changes button.

Now you should see the link that says "View photos of ____" under all your friends' profiles who have that link activated (meaning they didn't put their photos on private) so you should now be able to see tagged photos. Again, this link only shows if the person has photos of themselves that are tagged.

there's a setting where he can set his tagged photos to let himself view it only

Hi Rhendy,

If one of her friends [who is not blocked] is viewing your album, she will be able to see that the girl is tagged. I think that if you block someone, then tag them in a photo (although suspicious) will not write to their wall that they have been tagged. 

- Jeff