Polarity

Ketene is polar because there are an uneven distribution of electrons so there is an uneven charge. There is a positive charge where the Hydrogens are and and a negative charge where the oxygen is as you can see from the dash model before.

Covalent of Ionic???

Different words are used in front of either covalent of ionic to further describe the bond that is being analyzed after the difference of electronegativity is determined.
Absolutely Covalent- a difference of 0                       Very Little Ionic- a difference of 1.8-2.0
Very Covalent- a difference of .1-.5                          A Little Ionic- a difference of 2.1-2.4
Somewhat Covalent- a difference of .6-1.1               Somewhat Ionic- a difference of 2.5-3.0
A Little Covalent- a difference of 1.2-1.5                  Very Ionic- a difference of 3.1-3.4
Very Little Covalent- a difference of 1.6                    Absolutely Ionic- a difference of 3.5

Electronegativity of Bonds in Ketene
H  ----- C
2.2        2.5  --> difference of .3
This bond is very covalent

C ------ C
2.5         2.5 --> difference of 0.0
This bond is absolutely covalent

C ------ O
2.5         3.5 --> difference of 1.0
This bond is somewhat covalent