You should watermark your images, open your camera, hit the cog wheel, tap on the watermark, and edit. You can add your name, choose a font, and alignment placement. I'm terrible at taking selfies. My picture is grainy, but it's zoomed. Is that why?
Iso can affect the amount of grain caused by the amount of light either being allowed or not being allowed. However I think some grain adds a unique feature to photography as long as it's not overdoing it