For people who don't get it, back when the Syrian Refugee Crisis was going on, it was observed that woman really seemed eager to accept the Syrians (and the non-Syrians who were migrating along side them).

It was also observed that the majority of Syrian migrants, and migrants generally, were adult men.
https://www.pewresearch.org/global/2016/08/02/4-asylum-seeker-demography-young-and-male/
72% were male generally.

At the time, jokes were floating around that if the majority of the refugees/migrants were young women, that Western Woman would be reacting with xenophobic opposition.

Basically:
When a large amount of young men migrate, it increases the dating value of native women, while decreasing the dating value of native men.
When a large amount of young women migrate, the opposite occurs.

Since with the Ukraine, the refugees appear to be mostly women and children, the meme is suggesting Western Women will not be pro-refugee for them.

For context:

There have been lots of news around this Swedish PM who is against Ukrainian refugees. I'm not sure if it's her for this too, but I believe a similar thing was targeted towards Swedish men with Thai wives, also by a female Swedish PM

This made lots of people make some (in my opinion reasonable) assumptions, connecting the fact that Sweden and the rest of Europe have been getting and are still getting mostly male non-white refugees, but at the possibility of getting female or white refugees, they block the door

At least this has been my understanding of the situation and why it's often presented in memes