Likely not. But also, maybe?
Reproducing owned intellectual property is always copyright vs. trademarks vs. usage / sales can of worms, in that the devil is in the details.
The Nike name, swoosh logo and the “Just do it” slogan are all trademarked. Meaning they’ve gone to the trouble of protecting those intellectual properties so that other people can’t use (read: profit off or counterfeit) them.
Regardless of that fact, if you take a photo of , well, anything, *you* are the intellectual owner of the photo, i.e. you own the copyright to every work you produce.
The problem however has to do with *how* you’re selling the art. The circumstances.
If you’re selling it purely as a work of art, the law is probably on your side. Take that with a pinch of salt: I’m a fairly experienced photographer, but I’m not a lawyer.
Case in point, since someone else mentioned Campbell / Warhol: one of the reasons they never took any legal action is because it would be hard to prove that Warhol was somehow misrepresenting their trademark. Nobody viewing or purchasing his art could conceivably confuse it for a can of soup.
If it even seemed like you were somehow representing Nike itself, or selling on Nike’s behalf, they have legal precedent to send you a cease and desist (or worse).
All of that being said, nothing prevents a company from *pursuing* legal action against you.
The advantage to having round heads is that you’ll get circular diffusion. Practically this means you have more manageable hotspots. For shoot-through softboxes, umbrellas etc. this does make lighting a bit easier.
It also means much better control for illuminating a background.