After logging in to your twitter account, you might notice some changes to your profile, or you may notice your twitter background image is missing. The social network company twitter is replacing your customized background images with a neutral blue shade image.
According to Mashable, a twitter spoke person has told as follows :
“We’re removing background images from the home and notifications timelines on web for all users. Now, background images are only available where logged-in users will see them publicly (Tweet pages, list pages and collections pages). You can find help center content about customizing your design and where it’s visible on Twitter.”
By removing the background pictures, twitter is offering a clean and simple look to the new users. This also may be indication to the permanently disappearance of the background wallpaper. There is no more details available about this, you can visit the site for further information.