Bitcoin transaction size depends on the data of the transaction (inputs and outputs) and not the amount of bitcoin transacted.
Bitcoin transaction structure looks like this (this is the first transaction you posted)
{
"lock_time":0,
"size":225,
"inputs":[
{
"prev_out":{
"index":0,
"hash":"e71ccbb5b8abd8d4ba545c90b995489f473a5fc3fed4786e7f790137d98c4790"
},
"script":"473044022079ca69eb2a4a6dc002026e7c228ffec4ed28bc2e2c3f36ff6fd2bd544feea28d0220435dc4cc189077a36c93bf2f54de7cf4866829bf12d80e51674a80b87f8375c701210271511ff7d2c3142950be15a914e9988b338d4f9dda5de22d6f1a47c795550e4d"
}
],
"version":1,
"vin_sz":1,
"hash":"e6230cb27924b84ff46414b4eb3068a07dbbe0ccec31b15c7846975ecab0a008",
"vout_sz":2,
"out":[
{
"script_string":"OP_DUP OP_HASH160 9e7e8811f21c9e82757b16cfbc9b570697b7a8af OP_EQUALVERIFY OP_CHECKSIG",
"address":"1FT3LsfpWH3gHxvtjJjjUxFKkmXaJG41kR",
"value":5276500,
"script":"76a9149e7e8811f21c9e82757b16cfbc9b570697b7a8af88ac"
},
{
"script_string":"OP_DUP OP_HASH160 c87ba987900f1947dfafb352f3d89a531cfc40bf OP_EQUALVERIFY OP_CHECKSIG",
"address":"1KH4HZx4gSHtZaRCakaMMfMapVLipG9wej",
"value":7000000,
"script":"76a914c87ba987900f1947dfafb352f3d89a531cfc40bf88ac"
}
]
}
From that, you can see that the transaction only have 1 input and 2 outputs. If you use an additional input you'll get a new input data that starts from
{"prev_out" and ends with
"script":"strings"}. It's more or less the same thing for outputs.
That's what make transactions bigger or smaller. The value is only few bits while the input/output data can take several bytes.
You can see how the second transaction you posted (and any other transaction) by decoding the
raw transaction using
this tool. Compare those transactions and you'll see the obvious difference.