In the process of creating myself a database of all the snowtapult snowball overlays for reference, I noticed some of the snowballs don't seem to leave overlays on the character after multiple different test throws with the item, and a couple of the snowballs flat-out break the HA's image making the URL lead to a "Not Found" page for the (seemingly?) 10 minute time for the snowball overlay to expire. At least.... from what I could tell from repeated tests.

These are the snowballs with invisible overlays:

These snowballs temporarily break the avatar's image entirely:

Feel free to throw snowballs at me to test this for yourself xD (Since the HA system is a tad on the wonky side though the image might not update randomly ;~; )

EDIT JAN 31: Mistakenly added Well-packed Snowball instead of Tightly Packed Snowball but it's fixed, and added one I missed.