First Impression: A nice capture and doubt you had long to shoot this before it became a runny mess, the right hand 'ooze' looks like it was about to become a mini river. Almost a nice white background (the bit you missed has already been mentioned).
Composition: A little too central for me and would have prefered you to have balanced the sandwhich more forward on the glass to hide the rim.
Subject: Definately one for the ladies! Ice cream must be a tricky thing to photograph under lamps, I remember my dad went to a product photo shoot many moons ago and they used mashed potato instead of ice cream, it worked wonders and never melted!
Technical: The biscuit is nice and sharp and the ice cream is pretty well exposed. The background is almost white, just missed that top right bit. It might be the lighting but the stem of the glass doesn't look 100% straight.
Final thoughts: A nice clean and crisp shot, I gave a speed vote of 6 during the challenge and thought I may have been harsh, a 5.2 is underrated imho.