I have just uploaded a poster for a tv show. It's the only good quality image I could find for the show, and I believe it's an actual promotional poster used by the studio/network. The image has white bars around it, which when fully removed leaves the image with the dimensions of 501 x 748 (too short for the size requirements for the database).

I decided to just leave a white bar at the bottom of the image (so that the image could have 750 height). I know we're not supposed to resize images (change the original proportions of the image), but in this case, should the judgment be that it's better to have a small change in proportion, to get rid of any bars? Or is it best just to leave the image with the bar? Or should I not have uploaded the image at all and should now get it removed?

EDIT: Additional question- why is it, and I've just checked all of the entries, why is it that all the good quality posters I've uploaded, with perfect 2:3 aspect ratios, look lower quality/more blurry on the website than they actually are?