Thanks so much for sharing your images, Michelle. That really helps with the troubleshooting process!
Your original screenshot is 1365 x 819 (1.1 Megapixels). Since you've labeled your image with _NOPROCESS_, Rise won't try to optimize the weight of the published output by compressing your image, but it will shrink its dimensions to fit the block you've chosen. In the example of a centered image, that's a maximum of about 960 x 612 in a desktop browser, and much smaller in a mobile browser.
Best Practice: Don't shrink or stretch media in your course.
We'd recommend starting with high-quality images that are already properly sized for your course. Scaling media up or down in your course can cause blurriness, especially if your images have text.
If images and videos are bigger than your block, they'll automatically be scaled down to fit, which can result in a loss of quality.
Please let us know if you have any other questions!