add a mapping picture

TS-0041-oneM2M-SensorThings_interworking.md

@@ -200,8 +200,8 @@ Thus the OGC/STA data model has to be represented in the hosting CSE. The Sensor
 The IPE shall map the 'result' attribute of an OGC/STA 'Observation' to the 'content' attribute of a oneM2M <contentInstance>, and vice versa as shown in Figure 6.1-1.
 
 <figure>
-  <img src="media/data_model.svg" alt="data_mapping">
-  <figcaption>Figure 6.1-1: OGC data model cannot directly be mapped to oneM2M</figcaption>
+  <img src="media/data_mapping.svg" alt="data_mapping">
+  <figcaption>Figure 6.1-1: OGC / STA-to-oneM2M data model mapping</figcaption>
 </figure>