Nice looking snake and it's head to body ratio looks fine.However you should find that any disproportionate ratio of head v body size in most captive members of the Carpet Python complex is generally a result of exponential growth as a result of regular feeding regimes in captivity.
It depends on what other species of pythons of similar appearance you are comparing them to, ie: Green Pythons - yes, not as bulky. Scrub Pythons - yes, not as bulky but, when comparing them to members within the Morelia spilota complex the answer is NO, the Bredli head to body ratio is consistent with those of the Morelia spilota group. And what may add a little fuel to the fire is whether or not Bredli are a member of the Morelia spilota group (aka complex) or a separate species.
You may not be aware that prior to the separation and reclassification of members of the Carpet Python group there was originally just one recognized species, that being: Diamond Python - Morelia spilota spilota and one sub species, that being: Carpet Python - Morelia spilota variegata. Until Graham Gow reclassified Bredli's as Python Bredli in 1981 they were formally included under the banner of Morelia spilota variagata
The taxonomy originally used by Gow to elevate Bredli's (aka Central Carpet Python) to species level (Python bredli) in 1981 and as well as that used by Wells and Wellington to separate others of the spilota group and elevate to species level based on location, colouration and patterning was very poor but as the wording of the International Code of Zoological Nomenclature (ICZN) leaves considerable room for interpretation the elevation to species/subspecies for some members of the group was accepted. So at the moment we are all stuck with it. In addition the recent move to reclassify Bredli from Morelia spilota bredli to Morelia bredli appears to have been done without formal taxonomic treatment.
Due to the minimal standards of what has been acceptable to classify a species of reptile it leaves the question, "Are they truly genuine individual species or subspecies?", open and still up for debate. (It should be noted that dependent on whom you talk to the terms species and sub species relating to an individual taxon are acceptable to the taxonomic community) So, without going in to too much detail, what that means is, that all members of the group can be referred to as a species ie:- Bredli Python (Morelia bredli), or sub species ie:- (Morelia spilota bredli), Coastal Carpet (Morelia mcdowelli) or (Morelia spilota mcdowelli). However; there is a valid argument they are all just phylogenetic representatives of the one species. That being "a group or complex of animals that are actually a single species which encompass a lot of variations", variations in the case of spilota mainly relates to colour and pattern" of which according to the ICZN, along with location, are not considered unique enough characteristics to elevate individual animals within a group to species level.
In saying all that, as it stands at the moment their individual classifications are currently accepted and as such valid. That is at least until someone bothers to look into their classifications.