Saw it somewhere and did not pay enough attention.  Decided to try... Dissolved the gelatin packet,  I did not heat too much as thought the alcohol would evaporate, so to the refrigerator went and did not 'set'.  

Gelatine cubes of gin and a piece of fruit (mandarin) suspended inside, but poor result .  What went wrong ?  Does it need boil hot activation ? 

Put the gin in the freezer first and don’t add too much

Mix the gelatin first and let it cool a bit before adding the gin