The Two Twilights _{(20181022, colourised 20181207)}
 
Twilight (on the left, generation 1), the inspiration of Twilight Sparkle (on the right, generation 4).  
G1 ponies are generally more horse-like and the act of licking being a horsey thing, poor Sparkle has to endure it. She doesn’t want to upset her ancestor, though, a princess knows how to endure that. I heard that she tastes Twilicious.
 
You might notice that I tried to stay close to the respective originals, such as…  
…the conformation of the pony  
…black vs dark coloured outlines  
…solid vs gradient irides
 
I also fiddled around with different techniques.  
Most parts of Twilight Sparkle have multiple layers of colour, up to seven that is.  
While Twilight often has a single colour only, where lighter parts got filled by applying estompes (paper rolls).
 
I wonder if I should have drawn a background.  
It would need to be subtle that doesn’t take the focus.  
Maybe some faint blue and green colours hinting sky and land?  
Or should I just leave it as is?  
Do you have any suggestion?
 

 
References:  
https://derpibooru.org/images/1894252  
https://derpibooru.org/images/1894253