there are also no underlying rights here to purchase, refers to the word emoji and the image of the emoji. Sometimes, the words, images, shapes or characteristics of an object or a character are protected by trademark, trade dress, design patent, copyright, or some combination of these. Emoji, according to this article, is not so protected.
According to original the sentence, Lego is protected. The introductory phrase makes clear that Lego is unlike the unprotected emoji.
And in answer to the side comment by the OP, the bidding is apparently for the treatment or pitch. This is a presentation by an author, usually a screenwriter or producer, who has crafted the outline of a story which is protected by copyright and certain other laws, even though the subject of that treatment (in this case the emoji) is not protected. The character of Abraham Lincoln is not protected, but a pitch or treatment for a movie about Honest Abe (such as Lincoln as a zombie killer) could be.