The "mascot" in this photograph is a toy elephant.
 
The Electrical Experimenter, August, 1917, page 230:

BRITISH  WOUNDED  HEAR  LONDON'S  FAVORITES  VIA  TELEPHONE.
Hospitalized soldiers listening to Electrophone
    The free Electrophone Service, contributed by public-spirited people of London to the hospitals in that city, includes an installation by which a hundred patients can listen, whilst lying in bed, to the performances transmitted from the stages of the leading musical comedy theaters and music halls in London. The accompanying illustration shows some patients, with their mascot enjoying a performance. It is probable that some similar arrangement will be made in this country when the regular and auxiliary hospitals become filled with wounded soldiers and sailors. The telephone has made unprecedented strides in America where there are more telephones per capita than in any other country in the world. There are more telephones in New York City than in all Europe.
    Hence, with such extension telephone facilities available, the American convalescents will surely fare as well as their allies. Connection with band and orchestra concerts would seem very suitable.