I have Morelia that do exactly this, only ceasing for approx 4 days after feeding then resuming - They usually take up the position above the location where they are fed in their enclosures. They are not aggressive or snappy when in this stance. Some of these snakes are adults and on 2 or 3 week feed cycles. I believe it is purely opportunistic which is outlined as characteristic of their behaviour in the wild in a number of reference texts I have. Their formation directly above where they are fed in their enclosure also lends to this theory.
If you are feeding the right volume (10-20% of bodyweight every 7-10 days) he should be fine. It is rare to *need* to deviate much from this. If he is underfed he may well be hungry but I wouldn't assume he was hungry just because he is sitting like this unless you are underfeeding based on his weight. As you have not provided any further details (weight, food weight, frequency etc...) I am making the assumption that this side of things is all correct. Also it is a good idea to weigh your food items. I have seen what people call 'Fuzzy Rats' vary significantly in size/volume from supplier to supplier.
I would have *huge* snakes if I fed them every 4 days when they assumed this stance. If your feed volumes are correct and the snake is not showing food aggression towards you I would not be concerned - A quick check of animal weight and food weight will give you the answer about likelihood of strong hunger or wishful thinking.