It is always a little difficult to compare two guns holding them side by side as the differences can occur in any direction, and usually occur in multiple directions.
Glock classifies the G29 as a “subcompact” - same classification they give to their G26 and G27.
Glock classifies the G19 as a “compact” - they don’t have a gun in 10 mm that they classify as “compact”.
Yes, the size of the G29 is bigger than the G26, but just a little bit smaller than the G19 when it comes to barrel length and (even bigger difference in) capacity. Yet, the G29 weighs more than the G19.
It is my understanding that jf89 was looking for a 10 mm Glock that Glock classifies as “compact” - thus my answers.
But, putting the guns side by side, I agree that they start to look very similar in size.