generate.sh

#!/bin/bash
# this script requires
#  - bash (or similar)
#  - wget (or manually download the source images)
#  - convert (imagemagick)
#  - gifsicle (https://www.lcdf.org/gifsicle/)
wget -c 'https://scontent.cdninstagram.com/hphotos-xfa1/t51.2885-15/s320x320/e35/11248385_991083787599828_642737356_n.jpg'
wget -c http://i.imgur.com/CUhcR.gif

# prepare refp template
convert 11248385_991083787599828_642737356_n.jpg -rotate 268.1 -crop 290x143+25+12 \
    -size 68x46 xc:white -alpha set -geometry +131+38 -compose dst_out -composite \
    -size 68x44 xc:white -alpha set -geometry +131+99 -compose dst_out -composite \
    refp_template.png

# prepare sparkly layers
gifsicle -k256 CUhcR.gif -o simple.gif
gifsicle -U simple.gif -o unopt.gif
#convert unopt.gif -resize 50% interm.gif
convert unopt.gif -resize 98x120 interm.gif

convert interm.gif layer.png

# put layers into the template
for a in layer-*.png
do 
     convert -page 290x153 -size 290x143 -geometry +0+0 refp_template.png \
             -page 98x120+133+41 $a \
             -page 290x153 -size 290x143 -geometry +0+0 refp_template.png \
             -layers flatten \
             -trim \
             "mod_$(basename $a .png).gif"
done

# render gif
gifsicle -l -O9 mod_layer-* -o modded.gif