The early result shown in your photograph is not ideal, but it is a possible and actually predictable complication of lip injection. As a Plastic Surgeon and experienced injector, I would not be pleased with this result, but would also be able to counsel and address it. Don't worry - if the proper filler was used, things will be okay.
Soft-tissue fillers for the lip provide volume and shape, but are eventually resorbed by the body. The function of the filler comes from volume that is applied and molded, as well as the technique.
1. All filler application will cause some swelling initially; that subsides.
2. Filler is often injected from the corners of the mouth, and blood vessels there can bruise and swell. Side effects should be transient and mild, and include pain bruising, swelling, and redness at the injection site.
3. Good technique reduces these problems. Rapid injection and high volume are associated with increased rates of adverse effects.
4. Actual allergic reactions to hyaluronic acid filling agents are rare.
Fixing the problem:
You can start by doing lip massage to ensure the filler is spread evenly. As well, time will allow the swelling to improve.
Ultimately, if this were the result with my patient I would expect them to come back to my office. In the rare case of misplaced or excessive injection of filler, hyaluronidase can be used to treat.
Feel free to contact me with further questions.