The maximize / minimize functionality is optional in the container design, sounds like the designer did not include it.  However, you can make a simple modification to the container files if you would like to try that and see if it looks OK.

Find the particular container file, it will be in a folder somewhere around "\Portals\<your portalid>\_default\Containers\<name of skin pack>|".  The container file will be named <container name>.ascx.

You'll need to "register" the functionality by adding this line near the top of the file:
<%@ Register TagPrefix="dnn" TagName="VISIBILITY" Src="~/Admin/Containers/Visibility.ascx" %>

Then in the HTML, you'll need add the tokens which actually give you the min . max buttons.  That would look something like this:
<dnn:VISIBILITY runat="server" id="dnnVISIBILITY" /><dnn:ACTIONBUTTON5 runat="server" id="dnnACTIONBUTTON5" CommandName="ModuleHelp.Action" DisplayIcon="True" DisplayLink="False" />

That would probably be just an element at the end of the same line that contained the tokens for inserting the action menu.

I realize this is a little cryptic... you can always ask the skin provider if they have a version that has  the min /max buttons already nicely formatted.

---

Scott Willhite, Co-Founder DNN