Well here is the deal, unless they are meat filled or filled with something that has egg, meat or milk, technically speaking, a yukkuri is a ideal vegan food, at least from the technical side, it clearly would raise some questions about if that doesn't undermine their whole ideological statement of "not eating sentient stuff". But remember that there are 2 types of Vegetarians, those who eat ony veggies because it's what they like, and those who eat only veggies out of ideology.
I suspect this pic was meant to raise such discussion.