This labeling is designed to mirror the full text availability of that publication that your library can access. Some resources provided by your library may contain journals with and embargo period. These embargoes provide only index information for newer issues but do not contain full text until weeks, months or years after they were originally published.
If you encounter an article you are still very interested in accessing, please contact your library to inquire about options to obtain the full text and they may be able to help you via inter-library loan or some other means.
Note that this label also indicates that there are additional issues that DO contain full text and they are denoted by not having the orange bar next to their issue as seen below: