In music, a single is a short record, usually featuring one or two tracks as A-side, often accompanied by several B-sides, usually remixes or other songs. Most singles have only one A-side and are named after this song, but some may have a double A-side (a famous example being Strawberry Fields Forever/Penny Lane by the Beatles), where two tracks are given equal billing in the title of the single.
In a dog show, judges familiar with specific dog breeds evaluate individual dogs for how well they conform to published breed standards, hence the more accurate term is conformation show (or, sometimes, breed show).
"Dog show" is often used by the general public to refer to any event involving dogs, such as dog sports, but in the dog world it more specifically refers to conformation competitions.
Handlers set up their dogs for judging so that their stance is perfect when the judge views them.
Saint George oil painting by Raphael

Boxing Day in the UK is traditionally a day for sporting activity, originally fox hunting, but in modern times football and horseracing.