To anyone who is wondering how to enable this feature on Twitter, you can go to your Settings and privacy → Usage → High-quality Images uploads. Here you can either use Mobile Data & Wi-Fi or Wi-Fi only which can be found on the default Never. The app then would compress the image less before uploading. In doing so, the resolution, as well as the upload file size, would increase and will ultimately increase the time it is being uploaded.
Also, another notable change Twitter is making on how images are shown in timelines. Before, the default image would always be in landscape mode, no matter what the orientation of the picture is. Using a machine learning algorithm, Twitter was able to place a fitting image that views the subject in the window. The images now would simply be on your timeline in full size. As of the moment, the updates have not yet been rolled out to every user of the application.