This should do what you want. We dir and search for all .jpg
files in the source folder, then check if it exists, if it does, append a number using a counter, if it does not exist, we just move it..
@echo off
setlocal enabledelayedexpansion
set "source=D:\source\"
set "dest=D:\destination\"
set /a cnt=0
for /f "tokens=*" %%a in ('dir /S /B /A-D "%source%*.jpg"') do for /f "tokens=*" %%b in ('dir /B "%%a"') do if exist "%dest%\%%b" (
set "ext=%%~xa"
set "fname=%%~na"
if exist "%dest%\!fname!(!cnt!)!ext!" (set /a cnt=!cnt!+1)
set /a cnt=!cnt!+1
move "%%a" "%dest%\!fname!(!cnt!)!ext!"
) else move "%%a" "%dest%\%%b"