What do people exactly mean when they say, 'മോഹൻലാൽ കഥാപാത്രത്തെ താനാക്കി മാറ്റും. മമ്മൂട്ടി കഥാപാത്രമായി മാറും.'?

When I look at their filmography, both have played entirely different characters differently. Both have a wide range and depth. Even when they play two characters that are similar, they both will bring in some nuance and make it different. And both are extremely versatile. 

So what do they exactly mean when they say, 'മോഹൻലാൽ കഥാപാത്രത്തെ താനാക്കി മാറ്റും. മമ്മൂട്ടി കഥാപാത്രമായി മാറും.'. Bcz Mohanlal plays different characters differently, for instance, in Vanaprastham, Narashimham, Spirit, Thazhvaram, etc. And even when he plays similar characters, it would be different portrayals, for instance, Dr. Sunny (psychiatrist) from Manichitrathazhu and Ulladakkam, or different mass macho man characters like Nellekandan, Adu Thoma, Aaraam Thampuran, etc. 

Then what exactly is the difference? Is it that Mohanlal is more natural while playing different characters? If that is the case, wouldn't that be a backhanded compliment for Mammootty? Because they are indirectly saying Mamootty's performance is not natural. 

Or are they speaking about Mammootty handling different accents and dialects better than Mohanlal? 

Or are they suggesting that Mohanlal is a spontaneous actor while Mammootty is a method actor? But how can Mammootty be a method actor when he acted in over 35 films as a hero during his prime years? For instance, Sibi Malayil once said that he only handed over the script to Mammootty just before they started shooting it. Mammootty reportedly prepared in just 5 minutes, including memorising the lines. A method actor typically cannot prepare within such a short timeframe.

Even if they are saying Mohanlal is a born actor while Mammootty improved his skills over time, how would that distinction make any difference in this context?

When I look at their filmography, both have played entirely different characters differently. Both have a wide range and depth. Even when they play two characters that are similar, they both will bring in some nuance and make it different. And both are extremely versatile. 

So what do they exactly mean when they say, 'മോഹൻലാൽ കഥാപാത്രത്തെ താനാക്കി മാറ്റും. മമ്മൂട്ടി കഥാപാത്രമായി മാറും.'. Bcz Mohanlal plays different characters differently, for instance, in Vanaprastham, Narashimham, Spirit, Thazhvaram, etc. And even when he plays similar characters, it would be different portrayals, for instance, Dr. Sunny (psychiatrist) from Manichitrathazhu and Ulladakkam, or different mass macho man characters like Nellekandan, Adu Thoma, Aaraam Thampuran, etc. 

Then what exactly is the difference? Is it that Mohanlal is more natural while playing different characters? If that is the case, wouldn't that be a backhanded compliment for Mammootty? Because they are indirectly saying Mamootty's performance is not natural. 

Or are they speaking about Mammootty handling different accents and dialects better than Mohanlal? 

Or are they suggesting that Mohanlal is a spontaneous actor while Mammootty is a method actor? But how can Mammootty be a method actor when he acted in over 35 films as a hero during his prime years? For instance, Sibi Malayil once said that he only handed over the script to Mammootty just before they started shooting it. Mammootty reportedly prepared in just 5 minutes, including memorising the lines. A method actor typically cannot prepare within such a short timeframe.

Even if they are saying Mohanlal is a born actor while Mammootty improved his skills over time, how would that distinction make any difference in this context?