A random shot of my calculator 5000 miles from home while I enjoy a beer near the Pacific. We had been discussing how much water was on earth and what size of a ball it would make. I have no affiliation with the brewing company so apologies for the product placement.
Yes, looks like coated aluminium - not unlike a can but a little thicker and with no sharp edges. I've not seen these before but I think they are disposable/recyclable - i.e. a replacement for a plastic cup and far more pleasant to drink from. I took mine home as a souvenir, but I have had to unsquish it today taking it out of hold luggage.
That is a beautiful picture, and it looks like you're having a lovely time! Plus, I can show my wife that I'm not the only one who brings a calculator on vacation!
Yes, in fact before I got my DM42 I had one holiday where we had no internet access in the evenings and as the children were small and slept early, I didn't have much to do but I was able to learn a lot about using and programming free42.