Syogren:
Glitch: Hmm, well Missingno obviously wouldn't count but does Porygon-Z? Well let's look at what Porygon-Z is. Porygon-Z is an unauthorized evolution/upgrade to Porygon2 via a Dubious Disc. So it seems to be slightly based off hacking/modding. However Porygon-Z acts, well, glitched up indicating it also represents a computer program getting a virus and getting its data corrupted causing glitches and bugs. So altogether it's not that Porygon-Z represents a glitch but rather a malfunctioning computer program and the various things associated with it.
I'd say maybe this is one that needs to be specific. For example on the list I have "Communication Failure Bug" which is a type of glitch.
Water Droplet/Storm Cloud: I'd say that's maybe too close to Castform, specifically its Rainy Forme.
Sub(marine Sandwich)/PBJ Sandwich: Hmm, a sandwich really isn't its own thing but rather a combination of foods.
Window/Broken Shards of Glass: I think "Stained Glass" covers both.
Empty Bag: Not an empty bag, though I'd argue Delibird's bag-like tail might fulfill this. We also have other kinds of "bags" or other container devices on the list.
Space: This is something that sounds like needs to broken down into specifics, in fact there are several space things on the list. Also Palkia.
Toast: Can we take it back a few steps to a Pokemon based on
"Wheat"?
Cheese: Hmm, sure. Surprise we don't have it already.
Closed Fist: Hitmonchan.
Foot: Hitmonlee.
Amalgamation of disembodied hands/feet: Hitmontop? Erm, unless you can link it to a mythical creature I'm going to say that is too abstract.
Computer Icons: Ditto. Joking aside I think that may be too broad also for the most part computer icons are just symbol representing emotions or objects which can be a thing on their own.
Computer: I think Metagross sort of counts as one (and Porygon is a digital Pokemon). Also I feel a computer is a sum of parts and not a single thing on its own, sort of like with the sandwich.
Sausage: Already got Hot Dog on the list.
Existential Crisis: Ooh, I like this one!
Spatula: I think that'll fall under "Kitchen Utensils" which is on the list.
So new things added to the list: Wheat, Cheese, & Existential Crisis.
Also I have a batch of things myself to add to the list so here's the overall update:
PLANTS/FUNGUS: Hydnora Africana, Lithops, Bladderworts, Bat Flowers, Angel Trumpet, Telegraph Plant, Blue Passionflower, Welwitschia, Shaggy Ink Cap
FOSSIL:
Bug: Mimetaster, Marrellomorph
Other: Evolution of Primates
MARINE:
Clam: Clam Shrimp
CONCEPTS: Existential Crisis, Carollers, Spelling Bee, Tyromancy,
Film: Phantom of the Opera
OBJECTS:
Food: Wheat, Cheese