Well.. it isn't an internal window to mushclient, it is known as a out-of-process server. In other words you are having it talk to an external program. In both the case of a seperate image window or Internet Explorer object you link it through scripting like:
Sub loadIE()
Dim Handle
Set Handle = CreateObject("InternetExplorer.Application")
Handle.Navagate "c:\MyMudPics\Fred.png"
Handle.Visible = True
End Sub
Note... To make your own you would use Visual Basic to create an activex program with a simple picturebox, add some code to rescale it and the window depending on size (or even adding scroll bars, etc.), then since it doesn't actually need to talk to mushclient at all you would need is:
Sub loadMyApp()
Dim Handle
Set Handle = CreateObject("MyApp")
Handle.Display "c:\MyMudPics\Fred.png" '<--- Your public sub in the program you made for resizing the window
'and displaying the picture.
End Sub
The drawback though is that IE supports png directly, but the 'standard' libraries for most compilers don't, so you would have to use jpg, gif, etc. One alternative to this is to create your VB program and add a 'WebBrowser' control to it instead of the picture box. This would if done right provide 'most' of the function that IE has, but none of the extra junk that makes it so bloated.
To do this 'according to my 1-2 year out of date book' you would:
1. Create a new ActiveX EXE
2. Add the Microsoft Internet Controls (from Components) to the project.
3. Place a WebBrowser control on the form.
4. Add a sub to support the .Navigate function:
Public Sub Navigate(URL AS String)
On Error Resume Next
WebBrowser1.Navigate (URL)
End Sub
5. Make sure everything including the form is visible by default and you have changed any labels, captions, etc. to what you like. ;)
6. Optionaly add menus, button, a URL entry line, etc. to make it a real browser.
Then in your script you would just do:
Sub loadMyApp()
Dim Handle
Set Handle = CreateObject("MyApp")
Handle.Navigate "c:\MyMudPics\Fred.png"
End Sub
Which is basically the same as what you would do with the picturebox, but relies on the core of IE to handle everything. This means you coulds also feed it 'C:\MyMudPics\AllPics.html" as well, if such a web page existed. NOTE: I have not tried this, so can't be 100% sure it works or that I didn't leave out something important.