@Axa, that art was actually done in an 'out-of-bounds' area. The out-of-bounds are the areas with art that's visible to you, but you can't normally walk there due to the platform and the level design. However many players found little bugs and glitches in the game, such as street blending or ticket racing, to bypass there borders, and get to these areas. The special perk about these out of bounds areas is that they they don't have any gravity, as we can see. Items dropped will stay where they are, and with great patience and jump skill, one could have made a piece of art like this. Much earlier this year, the word Glitch was also reproduced by items of the same color in an out of bounds area in Corridor Six. It can also be noted that with the recently released feature of cubimal battling, it was possible to leave cubimals in midair, unattended. In a normal area, and it has actually been done to create ginormous dongs and toilets, it would have been possible to jump in midair and fight a cubimal, and with a large enough supply of cubimals, to create something like this.
Yes, but this this was a regular area. You can just jump and battle a cubimal, and it will freeze midair so no one can pick it up. The only way they could disappear is if someone battled another cubi at the same spot while you were online, then it would be returned to you. This is how many Glitchen, myself included, created cubi art in the final days.