What is the difference between getting no prefix key and getting a prefix key with empty string value in get_bucket_lifecycle API response?

Question

I'm running a python program that uses boto3 get_bucket_lifecycle_configuration API to get lifecycles set on a given bucket. I'm getting the following response -

    {"Rules":[
          {
             "Filter":{
                "Prefix":""
             },
             "Status":"Enabled",
             "ID":"deleteIncompleteMPU",
             "AbortIncompleteMultipartUpload":{
                "DaysAfterInitiation":1
             }
          },
          {
             "Filter":{
                
             },
             "Status":"Enabled",
             "NoncurrentVersionExpiration":{
                "NoncurrentDays":12
             },
             "Expiration":{
                "Days":210
             },
             "AbortIncompleteMultipartUpload":{
                "DaysAfterInitiation":1
             },
             "Transitions":[
                {
                   "Days":30,
                   "StorageClass":"DEEP_ARCHIVE"
                }
             ],
             "ID":"all-curr-GDA-30-non-curr-delete-12"
          }
       ],
       "ResponseMetadata":{
     }
   }
}

My question is that for ID deleteIncompleteMPU, the prefix value is an empty string "Prefix":"" but for ID all-curr-GDA-30-non-curr-delete-12 there is no Prefix key under the Filter key "Filter":{ }. Don't both things signify that the rule is set on the entire bucket? If no, then what is the difference?