It is an army uniform, and in the picture Gregor smiles, “inviting one to respect his uniform and military bearing.”) Food represents the way the members of the Samsa family feel toward Gregor.
Notably, it is Grete, the family member Gregor feels closest to, who feeds Gregor for most of the story.
As a result, the dignity the uniform conveyed to the father deteriorates, and Gregor again looks at him with pity.
(Notably, there is also a picture in the house of Gregor in uniform.
Attempting to summarize it will surely be a failure; a long, explanatory paragraph recapping the book would not be enough.
I’ll just leave the esteemed reader with the first sentence: “.” Metamorhposis is a Greek word, which literal translation is change of shape.
At the most deepest and transversal level, regardless of cultural background or other social factors, all of us humans share the same symbols: the mother, the father, the child, the god, the devil, the wise old man, the wise old woman, the hero, the trickster.
Jung does not, as far as my knowledge goes, investigate symbols related to food.
Mentioned right at the outset of the story, the picture of the woman in furs serves as a symbol of Gregor’s former humanity.
Exactly why the picture, which shows a woman wearing a fur hat, a fur boa, and a thick fur muff that covers her arms, originally attracted Gregor is never made clear (though it could be that it embodied Gregor’s desires—the presumably attractive woman may be sexually alluring while the furs she wears could signal wealth to Gregor).