When multiple images are posted on Instagram, the photos are usually compressed to save space. This compression process can cause the images to become blurry or pixelated, leading to a decrease in quality compared to the original image. Additionally, depending on the device from which the images are being uploaded, the resolution may be reduced, which can further contribute to a decrease in image quality. Furthermore, if the images are posted in rapid succession, the platform may compress them even further to ensure that they are all posted quickly. This could cause the images to become even blurrier and pixelated, resulting in a decrease in overall image quality.