Consistency with Style:
I think an "it's complicated" is warranted here: on the one hand, the shading and et cetera seem to match the LPC style really well. The outlines probably shouldn't be pure black. But otherwise, it looks pretty good.
However, it doesn't match the perspective... but on the other hand, it isn't trying to, given the nature of what it's trying to show: items that one might have in one's inventory. And the author is right that we don't really have guidelines here. So that actually makes judging this hard.
Quality and Skill:
Really, really well executed for what it is.
Quantity:
There's a good set of things people might have in an inventory here.
Judge's Opinion:
As said, I think this is a complicated entry. "Inventory item" stuff was out of scope for the contest, so simultaneously it's something one doesn't want to reduce points for, but on the other hand it's somewhat hard to judge fully.
That said, given I am giving 50 as "average artwork" (don't interpret this as school style scores) I am still giving this a high, above average ranking here. I do like it, and I think it will be useful for many people making LPC style games.
