"Have you ever seen yourself on TV?"
Translation:Viděl ses někdy v televizi?
"Ty ses viděl někdy v televizi?" With normal stress that is for me when you are surprised and wants him to affirm that he really has seen himself on TV. Your other sentence is equivalent.
In general, you can find use for almost any word order in Czech.
V televizi ses někdy viděl? He has seen himself in many things and you are asking if also on TV.
Někdy ses viděl v televizi? Similar.