My album art won't load even after adding it through get info>add artwork then pressing okay

SO, I recently made some music on my computer, and I wanted to add it to my phone. After uploading the tracks to itunes, I tried to add the album art I made. To be blunt, it isn't working. Here's what I've been doing: Get Info > Add Artwork. At this point, I see my art, and when I click on it, it changes from being enclosed by a blue square being free from ensnarement. Of course, I click on it so that it is highlighted as such, but when I click OK, nothing happens. Itunes shall seem to be in the process of loading, but then there's the three-note "do-do-do," and nothing has changed.

For reference, the artwork is a compressed jpeg file of dimensions 1625 squared.

What is going on with my itunes? Is this a known bug?