What is the difference between "in conclusion" and "by way of conclusion"?

When you consider other situations where "by way of" might typically be used -- for instance

By way of food, there was nothing in the fridge except a long-abandoned can of mouldy beans and a blackened banana

By way of reading material, the owner of the yacht had furnished himself with all 233 of Jeffrey Archer's finest novels

-- the expression seems to mean pretty much the same thing as "in terms of". Accordingly, by way of conclusion means roughly in terms of (a) conclusion, which in turn doesn't seem very different from in conclusion.

To my (American) ear, "by way of conclusion" means: "This is what I am offering as a conclusion". It may imply that this is not a real conclusion (in the technical sense of "given the arguments I have cited, I conclude that…). It may not be a "conclusion" at all, e.g. "By way of conclusion, let me mention a funny story I came across recently…".

When I as a reader encounter the phrase "in conclusion", I have every right to expect that the author will present a conclusion to, or at least a summing up of, the arguments and ideas they have presented in the article.