That looks like physical damage.

so is it fine?

I don't know what the spots are, but I would be more concerned with what appears to be a brown color. Why are you spraying with vinegar? I have never heard anyone talk about that. Euphorbias that are over-exposed to the sun (and that's kind of hard with a Euphorbia) MAY discolor so maybe that accounts for your browns, but -- I think your soil looks way too rich (maybe add substantial perlite to the mix) and I'm not sure spraying it with vinegar helps. The Euphorbias I have grown in pretty full sun, and I have most of them planted in simple, pure pumice.

Hi Kim. Just curious. How do you use the vinegar exactly? Apple cider vinegar or distilled white? Straight? Mixed with water? And what does it do for your plants?

Thank you,

Tyler