Why are empty blocks not all the same size?
On Monero Blocks I see a different size for blocks with zero transactions.
1157855 block size 210
1157856 block size 254
Usually, empty blocks can vary within a couple bytes, as monero amounts (present in the coinbase transaction even in "empty" blocks) are stored in a varying length encoding.
1157856, however, is a lot larger because it's got extra info in the extra field. It's probably been mined by MinerGate, who tends to add their own private information in blocks.