This is a meme, and a pretty old one at that? Don’t really see the issue here…appreciated not everyone grew up online, as it were, but the ‘what is he thinking’ meme has been around for donkey’s years. The implication is that she thinks he’s thinking about other women, and he’s thinking about something else entirely etc etc. That’s the joke. Feel free to be outraged if you want at the portrayal of women as jealous or something, but honestly this isn’t the worst thing affecting women today.
If you don’t wanna vote labour, you don’t wanna vote labour. But if you change how you vote based on misinterpreting a pretty well known meme then we have other problems.
Political parties rarely pull off memes though - this is an entirely unfunny and somewhat embarrassing example, but misogynist it isn’t.