User blog comment:Dimensionshark/Let's Get Invisible/Book & TV episode review (two in one!)/@comment-31910723-20180912123843

>there's what looks like a small smudge next to Max's (I presume this is Max we're looking at) right arm.

I always thought of that as being his arm being partly invisible, so you can see a bit of the attic's floor through his arm. I'm not sure, though.

Good review overall, I agree with pretty much all of it!