I tried to remove the user by selecting "Remove Users from Group" and tried to add this user again but that did not help and still the user details were not shown properly.
So now I clicked on the user name and there was a option to delete the user from the Site Collection (as highlighted). Once doing this the user was deleted from the Site Collection and I believe it has cleared any cache of the user details. Now I have not added the user again in the usual way. I clicked on the directory button which prompted a dialogue box as shown below:
This dialogue box was adding the user from the directory service. I typed the name of the user and searched the user and then followed the normal procedure of adding the user.. Eureka!!! All the user details now started to showing up when i clicked the user. So looks like some cache of user details was stored somewhere and this was cleaned after deleting from Site Collection and adding the user from Directory Services has retrieved all the user information.
You can also find interesting to read Data Sync Issue for a User between Active Directory and Site Collection