Are you looking at the Eggo logo in that filing from the 30s? If you look at the modern Eggo logo shown later in the filing compared to the egg roll trucks usage of it in “L’Eggo my eggroll” it is clearly so similar that it is hard to distinguish which “L’Eggo” belongs to the truck if you isolate them.

Parody and fair use are also significantly weakened in law when the use is commercial and without social commentary. Protected parody needs to be more than “I copied your branding style for my business”.

Again I’m not arguing that the law is moral or immoral, just that Kellog’s has a strong claim here under the law given that the branding as a whole is clearly copied from the Eggo brand, and that there is no evidence here that the food truck is trying to make fair use for the purposes of free speech, commentary or parody.

Is anyone going to confuse a waffle with an eggroll? No. But it is perfectly reasonable to think that the food truck is somehow associated with the Eggo food brand. Large corporations do stuff like operate offshoots and pop ups in adjacent niches. Look to IHOP’s brief marketing stunt rebrand to IHOB for an example.