BTW, images are both resized and compressed, if you use a visually low quality image (such as being able to actually see individual pixels) and it resizes it and it looks crappy, it'll still have a similar result with or without compression; a photo with high detail will produce a higher result after being resized.
The attached image has a resolution of 1,920px × 1,080px at 449 KB (459,885 bytes), and is compressed to 285.79 KB (292,646 bytes). Since it was under the indicated resolution (1920px) in the Control Panel it was not resized.
