Might need @kramer0 help...but what the hell does that mean?....
The two radars look at different sets of statistics, tailored to different positions. As @brap2
said, the length of each slice is determined by percentiles (with the 5th percentile being the center and the 95th percentile being the outer edge).
The one on the left considers Ross as a deeper midfielder, which is a bit misleading because while he often drops deeper during build-ups, he doesn't spend a lot of time in that area. Ross has good key pass numbers relative to deeper midfielders (of course, because he predominantly played further forward) and he's a good dribbler for a deeper midfielder (which is genuinely true even if didn't play much in that area). He's a pretty good passer (passing ability, long balls) and he doesn't commit many fouls relative to people who play further back (because he didn't really defend in that area for us). His defensive output is terrible for a deeper midfielder, a combination of Ross being poor defensively and the fact that he didn't play where defensive/box-to-box midfielders typically play.
The one on the right considers him as an attacking midfielder/forward, which is closer to the role he actually played. His passing and chance creation numbers (key passes, expected assists, expected goal chain, passing ability) are middle of the road for a creative player and adding in shots and expected goals doesn't really make him look any more impressive. He's still a pretty good dribbler but gives the ball away a lot relative to other forwards and attacking midfielders.
I think what that post really highlights is that Ross doesn't have a well-defined position at the moment. If he could find better shooting opportunities and create better chances (or even more chances), he'd be a good PL attacking midfielder. If he could take better care of the ball and contribute more defensively, he'd probably be a lot like Mousa Dembele (an excellent PL midfielder, especially w/r/t retaining possession and carrying the ball forward). As is, he's a weird player and I understand why Koeman doesn't seem concerned with losing him. Another manager might believe he can work on the weaker points of Ross' game and turn him into a very good player, which would probably be the appeal for Pochettino.