(I'm not a lawyer, I'm not your lawyer, and this isn't legal advice.)
You should ensure you have permission to use the image.
Most commonly, this will happen in one of two forms:
In either case, you should generally have explicit permission from the person who created the picture for you to reuse and share it.
(There are some cases in which "fair use" will apply and you may not need permission from the copyright owner, but this varies on a case-by-case basis. I encourage you to do your research on that area if needed.)