How to make in CCK a field like a grid
Presuming CCK=>Drupal 6, and without writing a custom module or custom compound CCK type, you could do something like this:


Create a cck content type, let's call it album_image, and in it have the following fields:

a.  Image field
b.  text field for title
c.  text area for description
Allow your users to create/edit these content types and fields via permissions
Create a view that returns all album_images created by the logged in user
Add a node reference field to the user's profile (The Content Profile module is an easy way to do this) and restrict it to one result, and call it for discussion here default_image.
Within CCK screens for the field above, use the view you created above to populate the "returned values" for the node reference instead of just selecting a content type.
Now, when your user edits his or her profile, they can select one album_image as the one they want displayed.


Now within your user profiles you have a field called field_default_image that contains the nid of the album_image your user wants to have displayed on his or her profile, so you can then load that up to get the image and use that wherever you need, eg, within whatever preprocess functions you use within your theme to paint the profile.