[Image description: image of text which reads "I like when men explain basic things to me because in my mind it's not mansplaining, it's more like when a toddler is really excited to tell you about dinosaurs and you're like that's right cutie! You're so smart!! Only one of us is being condescending and it's me", to which Shawn replies "if you have to announce when you're condescending, you're doing it wrong."
OP replies "that's a great observation, Shawn! Great job!" with a heart emoji]
Its both, except in the case of this post where the person is clearly being snarky and trying to put this woman down.
Most mansplaining is a man trying to be helpful. The issue arises in that they try to be helpful in situations where, if it was another man, they wouldn't try to be helpful, because they'd assume the man already knew the thing.
An obviously stretched out example, but, if someone was dreadfully thirsty and I, out of the absolute kindness of my heart, tried to offer them advice like "Gosh, that sounds awful. I'm so sorry. Have you tried drinking water? I've been thirsty before and water always fixes me right up", I'm sure we'd all agree this is misplaced advice and probably reflects on my perception (or presumptions) of their intelligence.