Go advanced, select the paper clip icon, upload the pics you want
then type some text, then select the paper clip icon again and select the attachment you want
ScreenHunter_02 Jun. 04 19.55.jpg
Write some more text, then select the paper clip icon again, select another attachment
ScreenHunter_02 Jun. 04 19.55.jpg
Is this what your trying 2 achieve?