Translation:Am I pretty?
So either the tone mark on standalone 'pìao' is wrong, or the spoken audio. The spoken audio has tone 1 (high tone), piao1, but the pinyin has the sign for tone 4 (falling). They do not match.
In the full context of 'pìaolìang' it appears both words take the 4th (falling) tone. But the tone mark or audio for the standalone word needs to be reviewed.
You're right! The problem is that 漂 (alone) have several readings, namely piāo, piǎo, and piào! I suppose that since these tips' audios are computer generated, they probably can't solve this easily! I doubt that Duolingo develop their own speech synthesis library, so they have little to no control over this! Ideally they'd have native speech audio tailored for every exercise, but I also doubt that'd come anytime soon...
I don't get why here the adjective can modify directly the subject without 很. Is it because it's a question?
When this (吗？) is added it will be asking listener a question of the previous statement which in this case is (我票亮) for an opinion.
(I am pretty) 我票亮 + 吗? = (Am I pretty?) 我票亮吗
Just like Trixie omg.
No, only when you turn a statement into a yes/no question. You don't need it if there's already a question word like who/what/where