That's a fair point, although I'm not sure I'd personally categorize it as "actively deceptive", I agree it could be a lot clearer about "Emissions", and empirically you're clearly right that is has some folks confused. To be charitable, like all science communication it's trying to simplify a very nuanced topic and probably could be improved. I do think the illustration of how leafblowers pollute at ~300x the rate a car does is largely true, and the GHG/environmental impact is a lot messier than just primary CO2 emissions.
(Disclaimer: I've never met or interacted with Nicole, but I know people that have, so I'm likely biased to assume good intent.)
I'm not sure about actively deceptive. What else does it mean? Hydrocarbon emissions are what you get when you burn hydrocarbons - H2O, CO2 and CO. If it's referring to a different thing, it's not a hydrocarbon emission.
The image, and the claim within it, is actively deceptive because it's not true.
It's a little messy, and it's not clearly disambiguated what concept the artist is referring to. I agree "Hydrocarbon emissions" could reasonably mean what you get when you burn hydrocarbons, but that definition can also include literal "Hydrocarbon emissions": uncombusted or partially combusted hydrocarbon fuel being emitted out of the exhaust after ignition due to non-ideal combustion. Like you mention, this is alongside CO, as well as elemental black carbon and other trace combustion products like NOx etc...
You're right that there isn't orders of magnitude more CO2 from a two stroke, but there are orders magnitude more CO, as well as these literal "emitted hydrocarbons", which I think it what the direct claim the art intends to illustrate with either dinfinition. But the fact we're having this conversation is evidence the claim at the very least isn't clear.
(Disclaimer: I've never met or interacted with Nicole, but I know people that have, so I'm likely biased to assume good intent.)