The image isn’t about his age or cognitive abilities though. It implies that having a president who needs a walker is “no way to run a country,” which is ableist.
The president of the United States cannot speak coherently, he cannot remember the names of Dem donors he has met many times, he cannot function after 8pm, and he's risking handing the election to trump bc he won't drop out. There are bigger issues than this magazine cover.
You not only have knowledge of their intent, you don't even have a way to infer intent, except what's clear; this is a story about a guy who has clearly aged out of his ability to do the job.