I don't know how you have you resolution set on your computer but the pic should not completely fill the screen. I post using the % in my tags
I’m not complaining...I have cable internet.
My laptop screen is 1920 x 1080/18”.
But anyone on a phone...*whew*.
LOL
I use the width= tag, myself.
Never heard of a % tag.
Learn something new everyday.
:)