In design, the rule of thumb when creating copies of an image is to go from large to small—never the other way around. In other words, the larger the image, the better its subsequent copies will be.
Just by resizing the image from 2496 x 1664 pixels to 1024 x 683 pixels, the file size is now 331 KB. This is nearly a 40 percent reduction in file size from 556 KB. A huge improvement, but we're not there yet.
Blurring the background is actually quite effective in itself, but it also has another benefit from the art direction point of view: It helps draw attention to the important part(s) of the image.
After blurring the background, the file now weighs 185 KB. That's about a 67 percent reduction in file size from 556 KB. We're starting to get somewhere.
Here's the new image with the blurred background:
A huge win for optimization!