Why wouldn't they put a sticker on it? (It is very common for companies to put their logo/name on the products they purchase. For example, on the bridge cranes and stamping presses installed in the factories.)Or a teaser for AI day - though as was mentioned here on TMC, the main objective for robots would be to further properly automate the Gigafactories.
Grimes on TikTok re-tweeted and @LivBoere directly on Twitter
The thing is why a Tesla logo/ decal on both?
Tesla may have purchased them to help keep track of construction at GigaTexas and/or GigaBerlin. (They are often used to go through and map construction with LIDAR to make sure things are progressing as planned without the need for a human to walk through and inspect/take measurements.)