I don't really understand why the author chose hex for the file size to begin with.

The first table is all "3b", which I initially interpreted as "3 bytes". Spent a good ten seconds wondering how any executable could be only three bytes.

Or use the 0x prefix 0x15e2 looks like hexadecimal to me.

Once I understood what he was up to, I didn't mind his notation. I found it kind of fun to compare the values.