In that case, you are seeing the size of the symmetric key being used. The bigger numbers mentioned above (1024, 2048, etc) are referring to the size of the pub

In that case, you are seeing the size of the symmetric key being used. The bigger numbers mentioned above (1024, 2048, etc) are referring to the size of the public/asymmetric keys. The public keys are only used to set up the initial exchange of symmetric keys, which are then used to secure your browser's encrypted connection.