make gif! 50 is ms, loop is times to loop (0 = infinite), dispose previous (must go together) is a necessary thing in giffing if you have transparency, resize with that \> is “only shrink if larger”
convert -delay 50 -loop 0 -dispose previous *.jpg -resize 640×480\> output.gif
strip exif! convert -strip in.jpg out.jpg
(no you can't add, as of 2019)
watermark! you have to do the transparency yourself, then, composite -gravity SouthEast ./watermark.png in.png out.png
. if your image is too big, gravity is irrelevant I think, but it'll align a corner.