It depends on the placement of the speech/thought bubbles.
If I scroll down and see the bubble first before the picture, I'd definitely read what's in there before looking at the picture. However, if the picture comes first followed by the bubble at the bottom of the panel, then I don't have a choice but to look at the picture first before reading the bubble.
Now that I think about it, I'm mostly 1, especially when the bubbles are scattered everywhere, which is common in mangas. I read the dialogue first so that I can understand the character's tone and emotions the moment I look at the picture. Does that make sense?
SO.. . HOW DO YOU READ YOUR MANHWA/MANGA/MANHUA?
IS IT.. .
1. DIALOGUE FIRST THEN THE PICTURE
2. PICTURE FIRST THEN DIALOGUE?
ME: I'M DEFINITELY #1