A 12 g serving of electrolyte powder creates a small pile, while 1 gal of water fills a much larger container. You can visualize the powder as a mound 2.23 in (5.67 cm) wide and 0.936 in (2.38 cm) tall, contrasted against a glass of water that is 6.52 in (16.6 cm) wide and 8.15 in (20.7 cm) tall.

Biggest vs smallest
3.65× the size
1 gal of water vs 12 g of electrolyte powder
Typical adult or standard sizes; real ones vary.