There is no yes or no answer to this or a black and white. Basically you have to look at if what his doing with the pictures falls under fair use, there are four factors that has to be considered for fair use and they are . The first factor is whether the content is transformative and adds originality - which his content does since it's his own form of entertainment & niche so he already leans more towards this factor. The second factor is the nature of the copyrighted work, using factual information to create content is more likely to be fair - this factor I am not too sure about but entertainment must fall under it since the nature of his content is purely his own work and is original. Third factor states "Borrowing small bits of material from an original work is more likely to be considered fair use...However, even a small taking may weigh against fair use in some situations if it constitutes the heart of the work." He is borrowing pictures to emphasize his comedy and elaborate his jokes so I feel that it does constitute towards this factor as his not just using the photos to make content out of them/get easy views from instead he uses the photos to make his content even funnier combined with his puns. And the last factor "Uses that harm the copyright owner’s ability to profit from his or her original work are less likely to be fair uses" unless it's parody,critique or satire to which it can look like his using photos to put bad light on people however his videos are parody type videos so he has no problem with this. What his doing is providing his own type of entertainment and niche instead of just showing pictures without any commentary. This makes him lean more towards fair use but the deal with pictures is that you can still breach fair use. For example If you use pictures that you did not make on your thumbnails the owner of that photo can file a copyright claim against your video because he owns it and it's blatant thumbnail promotion/clickbait by using someone else's content. His also not stealing stock photos that you have to pay for either. To mention aswell tho someone can still send him a copyright claim if they own one of the photos he used and if he refutes it they can take him to court if they want to with their poor claim, but they obviously won't because he falls under US/UK fair use law so their claim would not hold up in court at all and they'd lose out on money as he will be compensated by them for any damages that they've done (to his image, revenue, daily life etc). Also to mention that you need to make sure you understand your own countries law as it may be different to UK/US law which are similar. Just because YouTube states that these things are fair your country may handle it differently. Hope this helps, I do go off sometimes