Q: Do I need images with higher resolution for the display on updated devices?
A: Yes and No. Yes, the higher the resolution of your image, the better the display. This depends on the device it is being viewed on, the size of the image and the size of the display panel. However, this is not recommended because the larger the image, the more Bandwidth it will use and possibly cause a slower loading time for the end user.
We suggest optimizing your images to the best of your ability (possibly lowering the quality to withhold less pixels) to fit the site page you are going to be displaying it on and the purpose the image will be serving.
Note: When utilizing a software package such as Adobe save the file in the format of "save for web" and upload at 80%.