I suspect it's because they haven't got all of the drill hole...

I suspect it's because they haven't got all of the drill hole results to provide a reasonably accurate cross section of the drilled area. As stated in the release "The majority of the results from this prospective area have now been received and highlight an 800m long zone that contains large high-grade intercepts of spodumene bearing pegmatites, that extend along strike and down dip in all directions."

The release then goes on to say "An interim resource upgrade is currently underway using the remaining assay results from the 2022 drilling program." I expect that the interim resource upgrade will include a cross section as it will have the results for all of the 2022 drill holes.

The plan section shows where drilling took place but it does not identify all of the drill holes for which assays have been received, so I believe there are probably a few blanks in between the known drill hole results to draw an accurate conclusion as to the shape of the pegmatite body.

Personally, I think that it's a positive result as the mineralisation continues to extend quite some distance and is of reasonable grade. I don't know if the depth is a problem, but a cursory look at LTR's Mt Mann deposit shows the bulk of its pegmatite at the 220-420metres and they're using underground mining to extract it. Whether the LTR grade is significantly superior to Manna's grades, I can't say, but the lithium mineralisation is at similar depths.