It took almost a year for Twitter's Android app to get the feature, but finally, the social network allows users to upload and load 4K images. The caveat is it's currently only live on Twitter beta v8.76 and above. Unlike the iOS implementation, where you press and hold the image to get the option, the Load 4K feature is accessible through the three-dot menu that shows up when you open an image.
If you want to upload 4K images, head to Settings and privacy > Data usage > High quality image upload. From there, you can select if you wish to upload high-resolution photos on Mobile data & Wi-Fi or whichever option you'd prefer.
Source: Android Police