"This block is then pushed in the blockchain, where it stays forever."

Please explain this then:

More than once, I have posted a comment and had it appear to be visible under a post, i.e. it appears to have been "accepted" by the network...

Then, later on, I go back and it is gone!

Based on the combination of your article and my observations of this phenomenon, would it be true to say that the Steemit User Interface may temporarily display a certain state before it is posted to the blockchain? And that, afterwards, if the block is "dropped" that apparent state is reversed and disappears?

Thanks for the clarifying description... ;)

😄😇😄