I have compact view. I tap on a thumbnail to make the image "full screen". In short succession I tap on the screen once, then touch and drag, which zooms the image.
Since I have it set to dismiss/leave "full screen" via of images by swiping the image up or down I need the tap before dragging to zoom into the image.
That wouldn't work on article images, as those link to the article.
I don't know if Sync ever had it, but Joey for Reddit allowed me to zoom into article images by holding down on them and then pinching with my other fingers. A bit awkward, but welcome nonetheless.
Yeah, if I remember correctly, on reddit this worked in sync. Just hold the finger and drag down to zoom in. Worked in images, videos, article images... And as soon as you let go with the finger, back to the normal list