It’s not real, it’s just a joke (unfortunately)
The only difference is that modifies the block itself.. which is something we can’t really do. Well, we can, but it modifies all instances of that block. One blocks are self-contained.
I think the rules for a one block are:
- It must be a block
- It must only interact with itself
you can do that if you do this
Yeah, I definitely think that you should be able to create a block inside a one block. One way this could be useful is displays. As you cant set color slots, but you can set a label of a block and use symbols, you can use a seperate block the user gets out.
Snap! inside a oneblock?
It might be possible to just fit an IDE_Morph in a block slot with some JS; but of course you’ld have to make everything in the slot half the size of a speck of dust
I think the best way is to create another canvas and resize and reposition it to fit into the block 
Oh wait, I think that could work
actually, that is a thing, i just forget where i found it…
Convert the IDE into a full image, shrink it down, then attach it to the block.
Touch events? Approximate where the hand has touched in that image, then emulate the touch in that position in the actual IDE.