Unable to get expected behaviour from multiple cursor

[TryerGit]

Hello,

I have recently begun using VsVim extension inside of Visual Studio 2019.

I am having difficulty replicating the behaviour specified in this message on an earlier post on this site.

Specifically, how was the first image obtained where the a in assembly is highlighted?

Was it Visual Studio's command Edit.LineDownExtendColumn?

I tried something similar but was not able to get multiline multiple cursor editing. I have mapped CtrlShftDown to Edit.LineDownExtendColumn. I then apply this over the start of 3 lines. Then, when I press c it immediately changes the first character of each column. How was the author of that linked post able to press cw ? In my case, press of c immediately triggers the change (of the single character highlighted) with no time left for the w of the word.

Explanatory image attached: