...Finally there's the ugly little "Fair Use" exception. If you’re only just using a portion of the face from an image, (as in your example) there's a good chance they could argue fair use..
"Fair use" is for critique, education, etc. I don't believe there's any fair use caveat when an image is being used commercially.
Section 107 of the Copyright law calls for consideration of the four factors in evaluating a question of fair use:
1.
Purpose and character of the use, including whether the use is of a commercial nature or is for nonprofit educational purposes: Courts look at how the party claiming fair use is using the copyrighted work, and are more likely to find that nonprofit educational and noncommercial uses are fair.
This does not mean, however, that all nonprofit education and noncommercial uses are fair and all commercial uses are not fair; instead, courts will balance the purpose and character of the use against the other factors below. Additionally, “transformative” uses are more likely to be considered fair.
2.
Nature of the copyrighted work: This factor analyzes the degree to which the work that was used relates to copyright’s purpose of encouraging creative expression.
3.
Amount and substantiality of the portion used in relation to the copyrighted work as a whole: Under this factor, courts look at both the quantity and quality of the copyrighted material that was used. If the use includes a large portion of the copyrighted work, fair use is less likely to be found; if the use employs only a small amount of copyrighted material, fair use is more likely.
4.
Effect of the use upon the potential market for or value of the copyrighted work: Here, courts review whether, and to what extent, the unlicensed use harms the existing or future market for the copyright owner’s original work.
So "fair use" is not a hard black line (commercial/noncommercial) without comparing all four factors, which requires a court to decide. Even then the courts may interpret the four factors differently. In a case last year
https://petapixel.com/2018/07/02/court-rules-copying-photos-found-on-internet-is-fair-use/ on the first factor, the court ruled the photo was used on a "commercial site" in a "noncommercial way".
The law is a pit of gray matter even for attorneys and you have to consider everything that the court might take into consideration. I already mentioned the "work for hire" exception, but there's also the "clean hands doctrine".
Legal Dictionary - Law.com The OP mentioned earlier that the photo in question was of a minor, and he didn't have a release. Not clear is if he posted to social media or if the minor did. At the least, without a release I would guess a defendant's attorney would argue
locus standi.
Standing
As I said earlier most smaller companies would take it down rather then incur further legal expense, a larger company with in house legal staff, may or may not. Collecting from either would likely require litigation. Sending takedown notices doesn't cost much, but before I went much further I'd contact a competent attorney versed in copyright law. It might suck, but sometimes winning the battle cost more then it's worth.