If you want the image stretched then try this:
#include <GDIPlus.au3>
#include <GuiConstantsEx.au3>
#include <ButtonConstants.au3>
#include <EditConstants.au3>
#include <GUIConstantsEx.au3>
#include <StaticConstants.au3>
#include <WindowsConstants.au3>
Global $Form1, $hImage, $hGraphic, $iW, $iH, $iW_Prev, $iH_Prev, $PicPreview, $ButtonPreview, $iW_New, $iH_New, $iPrev_Min, $hBitmap_Prev, $hBitmapGDI_Prev
_GDIPlus_StartUp()
$hImage = _GDIPlus_BitmapCreateFromMemory(InetRead("https://www.autoitscript.com/images/favicon/favicon-180x180.png"))
$iW = _GDIPlus_ImageGetWidth($hImage)
$iH = _GDIPlus_ImageGetHeight($hImage)
$iW_Prev = 572
$iH_Prev = 268
$Form1 = GUICreate("Form1", 615, 438, 374, 347)
$PicPreview = GUICtrlCreatePic("", 24, 152, $iW_Prev, $iH_Prev)
$ButtonPreview = GUICtrlCreateButton("Preview", 520, 112, 75, 25)
GUISetState(@SW_SHOW)
$hBitmap_Prev = _GDIPlus_ImageResize($hImage, $iW_Prev, $iH_Prev, 6)
$hBitmapGDI_Prev = _GDIPlus_BitmapCreateHBITMAPFromBitmap($hBitmap_Prev)
While 1
$nMsg = GUIGetMsg()
Switch $nMsg
Case $GUI_EVENT_CLOSE
_GDIPlus_ImageDispose($hImage)
_GDIPlus_ImageDispose($hBitmap_Prev)
_WinAPI_DeleteObject($hBitmapGDI_Prev)
_GDIPlus_ShutDown()
Exit
Case $ButtonPreview
_WinAPI_DeleteObject(GUICtrlSendMsg($PicPreview, $STM_SETIMAGE, $IMAGE_BITMAP, $hBitmapGDI_Prev))
EndSwitch
WEnd